Maximize Your Productivity As A Software Engineer [Part 1] - How This Course Works

As a software engineer, you're expected to get a lot done with very little time. The compounding problem on top of that is how incredibly easy it is to get distracted as a digital warrior. This course is here to teach you how you can move faster and waste less time. Here are the core parts of the lesson:

- Your instructor [Alex Chiou](https://www.linkedin.com/in/alexander-chiou/) walks you through his extensive 10+ year Silicon Valley background across top companies like Meta and Robinhood, explaining how he was able to be a high-performing tech lead at both those companies working 30-40 hours weeks (particularly at Meta).
- You'll understand why being productive as a software engineer is so hard and why being unproductive as a software engineer is so easy.
- We walk you through the course objectives. By the end of the course, you will:
  - 💯 Know the **true** most important productivity booster

  - 💡 Champion the right **mentality** to foster productivity

  - 🏃‍♂️ Use the right tactics to **move faster**

  - 🛡️ Have shields to prevent you from **wasting time**

  - 🤔 Learn how to **debug** a lack of productivity

If you want to learn how Alex onboarded at lightning speed at Robinhood, check out his in-depth case study here: [\[Case Study\] Becoming A Tech Lead Again In Just 1 Month After Joining Robinhood From Meta](https://www.jointaro.com/lesson/X8vpfJooDpsX915ouC00/case-study-becoming-a-tech-lead-again-in-just-1-m)

How To Accomplish Something Every Single Day

How do you make every one of your days productive?

True or false: People overestimate what they can do in 1 day while underestimating what they can accomplish in 1 year.

Which of these attributes should your singular daily goal have?

True or false: You should try to keep your goals purely inside your head instead of writing them down. This saves you time and prevents you from overloading yourself with too many notes.

How To Put The Interviewer On Your Side

At the end of the day, passing a software engineer interview is about convincing another person that you're competent. The best interview candidates behave in a way that naturally puts the interviewer on their side. Weak interview candidates behave in a way where the interviewer becomes their opponent. This video covers how to do the former.

Here are the core points:
- **Always be communicating** - Nobody can read minds. By regularly explaining your thought process, you are keeping your interviewer in the loop and giving them the maximum chance to fully understand you and your skill. Communication is an especially important axis for Big Tech.
- **Be very careful asking for hints** - If you haven't made a lot of progress on the problem, asking for a hint is effectively asking the interviewer to solve a good amount of the problem for you. This severely reduces the signal the interviewer gets on your abilities. *If you ask for hints too aggressively, you may be tanking your own chances.* For deep dive of the dynamics of interview hints, [check out our video here](https://www.jointaro.com/lesson/QFZxCLSuUDRYysvBBFLR/how-to-handle-hints-in-a-software-engineer-interview-without-failing/).
- **View your interviewer as a human not an obstacle** - While it's true that you need the rubber stamp from the interviewer to pass, focusing on that too much will negatively show in how you interact with and communicate with your interviewer. When you view your interviewer as another person and have empathy for their situation, you will understand what they're looking for and be much better equipped to show that signal.

Related resources:
- [[Taro Top 10] Effective Interview Prep](https://www.jointaro.com/playlist/HLBYxJI7D1j8STolrwum/)
- [Effectively Learning Data Structures And Algorithms (DSA) For Software Engineer Interviews](https://www.jointaro.com/lesson/XwpMMY3ss97zOrXJQ7Xr/effectively-learning-data-structures-and-algorithms-dsa-for-software-engineer-interviews/)
- ["How can I show to a Big Tech company that I'm likely to succeed there?"](https://www.jointaro.com/question/ZpqoWC1zi3wMTXBUsS2B/how-can-i-show-to-a-big-tech-company-that-im-likely-to-succeed-there/)

The Breakdown Of A Good Technical Question

Asking effective technical questions: 
- **Intention**: What is your high level goal?
- **Expectation**: What do you expect to happen? 
- **Mismatch**: What is actually happening?
- **Investigation**: What have you tried?

If you're interested in learning Android, check out the tutorial Rahul references:  [Tip Calculator - Build Your First Android App](https://www.youtube.com/playlist?list=PL7NYbSE8uaBCMVBVg6cskGzdYguj3CUP-)

3 Quick, Powerful Negotiation Tips

How To Discover Your Work Passions And Hatreds

Which of the following should you do to discover your work passion?

What of these is a legitimate, strong sign that something is a work passion for you?

- *Regularly take time to reflect on how much you enjoy your work, especially when you're earlier-in-career*.
- Write down everything you do. Here are some examples of common things software engineers do:
  - Writing code
  - Reviewing code
  - Meetings
  - Working with JIRA
  - Talking with cross-functional stakeholders
  - Fixing bugs
- Split all the items into 3 buckets:
  - Things you genuinely enjoy: Tasks/behaviors you are excited to do and can lose track of time doing them.
  - Neutral: Things you can do a good amount of, but in the end, you do it for work.
  - Chores: You *only* do it for work, and you actively try to minimize doing these as much as possible.
- From the top bucket (enjoyment bucket), try to craft your work life around that.

Related resources about soul searching and find your own path:
- ["I feel like senior engineers tend to focus on a specific area. How can I pick a specialization that's still relevant in 5-10 years?"](https://www.jointaro.com/question/xFEhcvfbJ2P0pYzZ4r6f/i-feel-like-senior-engineers-tend-to-focus-on-a-specific-area-how-can-i-pick-a-specialization-thats-still-relevant-in-5-10-years/)
- [[Masterclass] How To Choose A Good Company And Team As A Software Engineer](https://www.jointaro.com/lesson/0WEmTNZOMIh8xAdfO3JH/masterclass-how-to-choose-a-good-company-and-team-as-a-software-engineer/)

Top System Design Interview Mistakes [Part 1] - Intro

Hi, [I'm Sophie Novati](https://www.linkedin.com/in/sophienovati/) and welcome to [Formation.dev](https://formation.dev/partners/taro)'s system design course made in partnership with Taro!

In this video, we introduce our unique approach to preparing for system design interviews, focusing on improving interview skills rather than just technical knowledge. I talk about the components of this course like:

- Addressing common challenges like freezing up or appearing too junior during interviews
- Emphasizing the importance of problem focus, communication, engineering thinking, and design leadership
- Analyzing real mock interviews to identify and correct common mistakes
- Concentrating on interview techniques with minimal focus on technical deep dives, using well-known prompts for illustration
- Aiming to help candidates effectively apply their knowledge in high-pressure interview scenarios

If you need extra help with your system design interview, [Formation.dev](https://formation.dev/partners/taro) can provide you hands-on, personalized support. Join us here: <https://formation.dev/partners/taro>

Building A Career Without Applying To Jobs (From An Eng Director)

[**Daniel O'Shea**](https://www.linkedin.com/in/danieloshea22/) is a Director of Engineering at X (formerly Twitter) and a 3x exited founder. He founded Laskie in 2020, a platform to help people understand the job market, find full-time work, and take on moonlight gigs. Daniel built a robust job-matching platform with tens of thousands of candidates. Laskie was the first acquisition by Elon Musk at X (Twitter) in 2023.

Throughout his professional career, **Daniel has never applied to a job**. Instead, he leveraged his network to find opportunities where he had an unfair advantage, and then continued to seek opportunities from his jobs and professional network. Almost all engineers suck at this: sending connection requests on LinkedIn is not enough.

In this talk, Daniel will share tactical advice to better leverage your own network, along with lessons from his professional journey. He'll also share data from seeing 1000s of engineers looking for jobs as part of running Laskie.

- Daniel on LinkedIn: [**https://www.linkedin.com/in/danieloshea22/**](https://www.linkedin.com/in/danieloshea22/)
- Daniel on X: [**https://twitter.com/oshea**](https://twitter.com/oshea)

Additional expert networking resources:

- [**"How to network effectively in a tech event?"**](https://www.jointaro.com/question/wx6HewLcKbxNRfMBiAAI/how-to-network-effectively-in-a-tech-event/)
- [**"How do you network effectively within a company?"**](https://www.jointaro.com/question/DwT9GtdYK9nwFV3a7jrU/how-do-you-network-effectively-within-a-company/)
- [**\[Masterclass\] How To Build Deep Relationships Quickly In Tech**](https://www.jointaro.com/lesson/tyaPFMXPoz2pmzB7OVzt/masterclass-how-to-build-deep-relationships-quickly-in-tech/)

Getting To The Top 1% Of Amazon Engineers - Productivity Tips From A Life Engineered

Steve Huynh, from the popular channel A Life Engineered, talks about the 3 parts of his productivity system. After spending more than 17 years at Amazon and obtaining the coveted Principal Engineer title, Steve spends a lot of time thinking about peak productivity. 

Timestamps:
- 0:00 - Intro to Steve
- 0:40 - Why invest in a system for time management?
- 2:30 - Have a healthy relationship with notifications
- 6:02 - Optimize your schedule
- 9:00 - Optimize for impact (not comfort)
- 11:25 - How Steve organizes his time

Related questions:
- [When to check email to maximize productivity?
](https://www.jointaro.com/question/aBmMAXWqsQ8gYxyAJcpq/when-to-check-email-to-maximize-productivity/)
- [Is typing speed important as an engineer?](https://www.jointaro.com/question/JeBsvDeGQf01ritm98W0/is-typing-speed-important-and-what-speed-is-acceptable-for-a-dev-looking-to-work-at-faang/)
- [How do I estimate my sprint tasks better?](https://www.jointaro.com/question/3R6yRStSzDMmvLRCiMVV/how-do-i-estimate-my-sprint-tasks-better/)

Connect with Steve: 
- [Taro](https://www.jointaro.com/profile/aZJL3ucq9dQnscO09F4JDRkgPo72/)
- [YouTube](https://www.youtube.com/@ALifeEngineered)

[Masterclass] What Software Engineers Should Look For In Their Engineering Manager

Related resources:
- [Voicing Your Problems And Frustrations Productively](https://www.jointaro.com/lesson/elIKuK5Ody0xzVNmdnsR/voicing-your-problems-and-frustrations-productively/)
- ["My manager and I don't see eye-to-eye. How can I improve this relationship?"](https://www.jointaro.com/question/WWuU0HRpNu90J638iJPs/my-manager-and-i-dont-see-eye-to-eye-how-can-i-improve-this-relationship/)
- [Presentation Slides](https://docs.google.com/presentation/d/1Hk6oEtLAKBKI3jF5SvB7bPGZHZMoxx79VJIoA3N3Bk4/edit?usp=sharing)

[Masterclass] How To Get Promoted Faster In Tech

Related resources:
- ["How to drive my promotion discussion with my new manager?"](https://www.jointaro.com/question/nbYTuVbu3dqGlPALRGbR/how-to-drive-my-promotion-discussion-with-my-new-manager/)
- ["What does it mean to not have enough scope to be promoted?"](https://www.jointaro.com/question/bJuagPwOEEy5vkcXKkqh/what-does-it-mean-to-not-have-enough-scope-to-be-promoted/?playlistId=eZOEUatYEe7BBAZByuha)
- [Presentation Slides](https://docs.google.com/presentation/d/1LceOHzKxQ12LCtZvNu9OIXIE18UH_ldvW4gGZQewunA/edit?usp=sharing)

Avoid These Junior Engineer Mistakes With Code Review

- Do the work upfront to make your published code reviews look good.
- If you get feedback on your code review, incorporate it directly into the current pull request to make the commenter feel heard. Don't put off the feedback by saying you will do it in a new pull request and push the commenter to allow you to land the PR.
- If you just want to get high-level feedback on your approach and don't want to actually merge your PR yet, you can submit a "Request For Comment" PR, otherwise known as an RFC.
- If there's no good way to test your change:
  - A lot of the time, there probably is. Think harder about it.
  - If you can't come up with anything (e.g. you did a very basic refactor), just regression test and show that the codebase still builds/the app still runs.

Related resources:
- [[Masterclass] How To Do Amazing Code Review](https://link.jointaro.com/29jyjjRiaUBZ1htQ9) - This video is a clipped highlight from this masterclass!
- [One Diff, One Thesis - What Every Code Review Should Be Like](https://link.jointaro.com/5Ehehxt6jBR42ui1A)
- ["What can I do to quickly build my reputation as a junior engineer?"](https://link.jointaro.com/hxCTvumsQhUqRAbn6)

[Masterclass] How To Build And Grow Tech Products To 500k+ Users For Free

Here are our Top 5 points from this session:
- **Side projects are incredibly powerful** - They improve your portfolio, increase your coding velocity, and give you holistic experience around building products end-to-end.
- **Care deeply about quality** - Users notice when your app or website is buggy. Strive to cover all edge cases and provide a truly polished experience.
- **Eat your own dogfood** - The best way to know how to improve your product is to use it yourself. This was a staple of Meta's engineering culture.
- **Least clicks design** - At the end of the day, it doesn't matter how "pretty" your product looks if it isn't efficient. Think about how you can have your "hero flow" take as few clicks as possible.
- **Understand SEO** - Work backwards from what people will be searching for when they need a product like yours. Then have those words in your product title and relevant metadata.

Related resources:
- [Presentation Slides](https://docs.google.com/presentation/d/1lfSCWI_OUtchWpIEKwG8JkII8IUvBeACRqEJlnTErjU/edit?usp=sharing)
- [How To Come Up With Product Ideas That Get 100k+ Users](https://link.jointaro.com/7Q8cDrda23zv2omU9)
- [How Side Projects Make Recruiters Come To You](https://link.jointaro.com/rxqDDu4sgMQbP6LT8)
- [Why Side Projects Are So Powerful For Junior Engineers](https://link.jointaro.com/cFo3doiWDeE5dpa67)
- [How To Split Your Time Properly Between Work & Side Projects](https://link.jointaro.com/YFCmNrsdqhuMSeUw5)

Code Review MUST Be Fast, Otherwise The Team Is Unhealthy

- In the end, code review is a gatekeeper, so it has to be fast for the team to ship quickly.
  - This is especially true if you work for a high-performance tech company like FAANG or a hyper-growth startup.
- *If you're evaluating a team, definitely ask about what its code review culture and speed are like.* Not only does faster code review lead to smoother shipping, it also enables faster learning.
- It should take 1-2 days to get code review feedback, and even 2 days is pushing it.
- What's important to realize is that a lot of pull requests will take multiple iterations to be finalized. Let's say it takes your teammates 3 days to leave feedback, and you need 3 revisions before your PR is perfect. *This means that landing 1 PR took you over a week.*
- Have a focus block at the end of your day where you can review all open pull requests from your team to enable that 1 day turnaround.
- Code review is inherently a more selfless act as it unlocks someone else. *Doing lightning fast code review is an extremely powerful way to be a stellar teammate.* Alex got to most reviews within 2 hours.
- On the flip side, don't be too pushy asking teammates for code review. Wait for around a day at least before pinging them (unless it's an urgent PR).

Related resources:
- [Avoid These Junior Engineer Mistakes With Code Review](https://link.jointaro.com/agkYrLH8uuCv4UcPA)
- ["How do you suggest code review feedback where you think there’s a better way to do what they’re currently doing?](https://link.jointaro.com/y9sQNWiPqFct4ad2A)
- ["How can I write great code faster?"](https://link.jointaro.com/1h3FLBSJWxbVoEUo6)

Effective Communication Guide [Part 3] - Building Relationships

In order to succeed as a software engineer, you need people to like you. So how do you make that happen quickly? This lesson teaches you:

- **Relationships are all about trust** - The more someone trusts you, the more they will share with you, and the more effective your collaboration can become. The 1 on 1 meeting is the most mechanism to earn this trust.
- **Trust by default** - Trust is extremely hard to earn and very easy to lose. The best way to earn someone's trust is to give them a lot of your trust. This will trigger a response where they will strive to follow The Golden Rule, giving you more of their trust to make things balanced. For an example of trusting by default and earning trust lightning fast, check out [our deep dive into great mentorship here](https://link.jointaro.com/YdUM4JP89Sjh7ruv5).
- **Make small talk** - 2-5 minutes of small talk per 1 on 1 can go a long way. By talking about things outside of work, you are showing that you truly care about them as a person.
- **Be honest** - Tell it to people straight, and don't mince words. By showing that you're comfortable sharing what you're genuinely thinking, people will want to do the same. This is especially powerful when talking about problems.
- **Use humor and self-deprecation** - Everyone likes to laugh: It's a very human thing to do. Crack a joke here and there when you can. Self-deprecation is effective as it's safe (you are poking fun at yourself instead of someone else) and shows your humility.
- **Show thanks** - Don't take your colleagues doing great work for granted: Doing great work is always hard. There is really no such thing as giving too much thanks and making people feel too appreciated. *This is a severely under-utilized technique*. Giving heartfelt thanks is supremely powerful - You can turn someone's bad day into a good one.

Here's Why You're Doing Interview Prep WRONG

Most people do very shallow interview prep that doesn't actually help them learn. Lists like Blind 75 and Leetcode 75 are not enough to truly master the technical interview for Big Tech companies. 

In this video, Daniel proposes the "proper" way to master the coding / DSA interview so that you can walk into interviews and feel more confident. There are no shortcuts and no memorization -- instead, it's about going beyond the solution for a problem, and then understanding the nuances and process to get the right answer.

- Connect with Daniel on [LinkedIn](https://www.linkedin.com/in/danieltomko/)
- Checkout Formation as part of [Taro Perks](https://www.jointaro.com/perks/)

Relevant Taro content: 
- [Effectively Learning Data Structures And Algorithms (DSA)](https://www.jointaro.com/lesson/XwpMMY3ss97zOrXJQ7Xr/effectively-learning-data-structures-and-algorithms-dsa/)
- [Struggling With DSA? Don't Worry, That's Healthy!](https://www.jointaro.com/lesson/SPWYdMAu5XQX8ds9MxXc/struggling-with-dsa-dont-worry-thats-healthy/)
- [Masterclass on DSA interviews](https://www.jointaro.com/lesson/V4sTACzfOh22nMVcUV3w/how-to-ace-your-big-tech-interview-data-structures-and-algorithms-7172021/)

The #1 Principle To Remember When Authoring A Code Review

Bad Question vs. Good Question Example

Is the following a good question: What are the best open-source projects to work on?

"What are the best open-source projects to work on?" - How can the asker improve this question?

Is the following a good question: Any Java developers here who have worked on ML?

"Any Java developers here who have worked on ML?" - Why is this not a good question?

Is the following a good question: Does anybody know what the front-end engineering interview for Amazon looks like?

"Does anybody know what the front-end engineering interview for Amazon looks like?" - How can the asker improve this question?

Is the following a good question: Can someone recommend me resources for blockchain development?

"Can someone recommend me resources for blockchain development?" - How can the asker improve this question?

Is the following a good question: Is there anybody here who can refer me into FAANG?

"Is there anybody here who can refer me into FAANG?" - Why is this not a good question?

Asking questions is one of the most important skills for an engineer: However, so many engineers struggle with this and ask questions that are bad at getting answers. This is all even more important in the age of AI with tools like ChatGPT.

This video covers an in-depth example of a bad questions vs. a good question:

### Bad Question
*"I'm trying to load an image in my Android app, and it shows up blank. Any ideas on what's going on here?"*

Here's why this question falls short:
- It feels lazy as the asker doesn't share what they have tried already - Did they even do a Google search?
- There's no context on why they're trying to get an image to load - The impact of helping this person is unclear.
- There is 0 relevant code attached: This question forces potential helpers to ask a lot of follow-up questions to give advice.

## Good Question
The upgraded question is too long (check the video to see it), so here are the core points as to why it's better:
- The user attached everything they have tried.
- There's links to additional context if helpers reading the question want to dive deeper - Keep in mind that they're not embedded directly within the question as huge code blocks can be overwhelming.
- In general, it's very obvious that the asker put a lot of effort into the question and is respectful of everyone's time.

Related resources:
- [[Masterclass] How To Learn Quickly In Tech](https://www.jointaro.com/lesson/u9ldIvrTvV1wfWExccDR/masterclass-how-to-learn-quickly-in-tech/) - The full video where this clip was taken from
- ["How do you overcome the fear of asking stupid questions / bothering people when you need help?"](https://www.jointaro.com/question/vNE8kgpx2zdI1wACg9jA/how-do-you-overcome-the-fear-of-asking-stupid-questions-bothering-people-when-you-need-help/)
- [[Case Study] How Engineers Unlock Huge Impact With Artificial Intelligence (AI)](https://www.jointaro.com/lesson/gTQZbv0lmmypLPytqw5g/case-study-how-engineers-unlock-huge-impact-with-artificial-intelligence-ai/)

Properly Learning From Software Engineers More Senior Than You

True or false: What is built by a very senior engineer is more important than how they built it.

When observing very senior engineers, what should you look for to properly learn from them?

True or false: At the top tech companies, the very senior engineers make 5-10x more than their very junior counterparts because they work 5-10x harder than they do.

Which are good examples of questions you can ask when understanding a very senior engineer's behavior?

True or false: At the top tech companies, you are told less and less what to do as you grow more senior, working on more ambiguous projects while having greater freedom to choose what you work on.

As a junior software engineer, it can be daunting understanding the senior and staff engineers on your team. This video covers the mindset shift to make to start leveling yourself from properly observing them, achieving career growth without these engineers having to formally mentor you.

Here's the core points:
- **Observe more senior teammates' behavior** - Principal engineers will usually have 10x the impact of a junior engineer. They don't get there by working 10x as hard - We all have the same 24 hours in a day. Instead of asking yourself *what* these great engineers are getting done, ask yourself, "*How* do these engineers get stuff done?". Marveling over their much larger impact won't get you anywhere - You start really learning from these engineers when you start breaking down the path they took to achieve that impact.
- Here are more specific axes to observe:
  - **Communication** - How do these engineers share status updates and rally the team around their ideas?
  - **Direction** - How do they prioritize projects and select the best ones?
  - **Quality** - How do these engineers protect the sanctity of launches? What kind of feedback are they leaving in code review? What good habits do they have when they submit code? How do they facilitate system design discussions?

Related resources:
- ["What's the core insight behind quick growth?"](https://www.jointaro.com/question/nJ762p255cGyuth36H6w/whats-the-core-insight-behind-quick-growth/)
- ["How do you get the most out of mentorship?"](https://www.jointaro.com/question/IbuZydz0QzsVVqESVaxQ/how-do-you-get-the-most-out-of-mentorship/)

An Autistic Journey To Google Staff Engineer [L6] From Software Analyst - By Lee McKeeman

[Lee McKeeman](https://www.linkedin.com/in/lmckeeman/) is an autistic software engineer with quite an incredible journey: Across a whopping ~20 years of experience, Lee has worked at Amazon (where he was an engineering manager and bar raiser), Meta, and now Google.

Lee's career story is super long (watch the video to get the full picture), so instead, we're sharing some of the great learnings from Lee here:
- **School doesn't actually teach you software** - University is generally rooted in theory and overly abstract exercises, leaving you with a very basic raw coding foundation. While that certainly has value, it's not enough to make you capable of doing actual software engineering, especially in a team environment.
- **Debugging is a critical skill** - Lee started off as a software analyst, which was a role that was much more focused on diving deep and fixing issues as opposed to churning out new features. The experience Lee got here was extremely valuable and continued paying dividends across his career, even after he transitioned to SWE.
- **Help others and keep an open mind** - Everyone works in different ways and will be comfortable/uncomfortable in situations that don't match that of others. This includes the neurodivergent population like autistic people, those with ADHD, and more. Be a true teammate by being understanding and accepting of these differences. Assume good intent, and if you aren't sure how you can best support a teammate, just ask them!

To learn more from Lee, you should 100% connect with him on LinkedIn where he writes some of the best posts (and comments) on the entire platform: [Lee's LinkedIn](https://www.linkedin.com/in/lmckeeman/)

Here's some of the incredible wisdom Lee has shared on Taro:
- ["What does it mean to not require handholding anymore?"](https://www.jointaro.com/question/5vEWajcZlSi7nlohTGtJ/what-does-it-mean-to-not-require-handholding-anymore/)
- ["How to Balance Responsibilities: Prioritizing Personal Work vs. 'Glue Work' in a New Team Environment."](https://www.jointaro.com/question/9NL4LP40xHy5sgGMvsmB/how-to-balance-responsibilities-prioritizing-personal-work-vs-glue-work-in-a-new-team-environment/)
- ["Can someone elaborate on "always treating feedback as a gift"?"](https://www.jointaro.com/question/4DoEnMIq2ISadfAJuwp9/can-someone-elaborate-on-always-treating-feedback-as-a-gift/)
- ["What do career levels structure in big tech company look like? What are the responsibilities for each level?"](https://www.jointaro.com/question/qV5oikdcgs4GWmGeousX/what-do-career-levels-structure-in-big-tech-company-look-like-what-are-the-responsibilities-for-each-level/)

Tech Career Growth Videos

Our instructional videos provide software engineers with insights needed for career growth. Masterclasses go incredibly in-depth on a specific tech topic while case studies are real examples from established engineering leaders.