Code Quality

In this section, we focus on **code quality**, a crucial yet often underestimated element of ML interviews. Even if our model works well, poorly written code can seriously damage our impression. Clean, clear code reflects professional maturity and real-world readiness.

- **Mediocre code** may be functional but is hard to read—characterized by cryptic variable names, long repetitive functions, unclear logic, and little to no documentation.
- **Stellar candidates write clean, organized code**, breaking it into logical chunks with reusable functions and clearly labeled sections.
- We use **meaningful variable names**, write comments that explain the "why" behind decisions, and maintain a logical flow from start to finish.
- Our code is **efficient in design**, avoiding unnecessary complexity and maintaining smooth execution without over-optimizing.
- Ultimately, we recognize that **code is communication**—and polished, maintainable code signals we’re ready to contribute to real engineering teams.

If you want to learn even more from Yayun:

- Book 1 on 1 career guidance with her here: <https://calendly.com/your-friend-yayun/1on1>
- Follow her on LinkedIn: <https://www.linkedin.com/in/yayunjin/>

Evaluation

In this section, we explore **model evaluation**, a phase that’s often underestimated but critically important. This is our chance to show we’re not just optimizing metrics—we’re aligning our work with real-world impact.

- **Mediocre evaluation** involves simply calling `.score()` or reporting accuracy, with little explanation or context—a major red flag in interviews.
- **Stellar candidates choose metrics that fit the problem**, such as F1 score or AUC-ROC for imbalanced classification, or MAE over RMSE for certain regression tasks.
- We demonstrate awareness of **trade-offs**, like how boosting recall might reduce precision, and explain the implications clearly.
- Most importantly, we **tie evaluation to business goals**, showing we understand the cost of errors and what metrics matter most in practice.
- This thoughtful approach proves that we’re not just building models—we’re optimizing for meaningful outcomes.

If you want to learn even more from Yayun:

- Book 1 on 1 career guidance with her here: <https://calendly.com/your-friend-yayun/1on1>
- Follow her on LinkedIn: <https://www.linkedin.com/in/yayunjin/>

In this segment, we explore the importance of **Exploratory Data Analysis (EDA)** in machine learning interviews, especially during notebook-based exercises. This is a key moment to distinguish ourselves by demonstrating analytical depth and real-world intuition.

- We move beyond just **checking for missing values or printing basic stats**, which signals a surface-level approach.
- Instead, we analyze **feature distributions**, identifying skewness, outliers, and unusual patterns that may affect modeling.
- We examine **relationships and interactions between variables**, not just computing correlations, but exploring potential dependencies and dynamics.
- We assess **data quality**, including duplicates, inconsistent categorical values, and signs of data leakage.
- This deeper EDA shows that we can **interrogate the data critically**, a trait that interviewers associate with strong, production-ready ML practitioners.

If you want to learn even more from Yayun:

- Book 1 on 1 career guidance with her here: <https://calendly.com/your-friend-yayun/1on1>
- Follow her on LinkedIn: <https://www.linkedin.com/in/yayunjin/>

Common Pitfalls (Red Flags)

In this section, we’re cautioned against common mistakes that even capable candidates make during ML interviews. By knowing what to avoid, we can better showcase our understanding with clarity, relevance, and maturity.

- We avoid **math without context**—using complex terms without explaining their real-world application often hurts more than it helps.
- We steer clear of **overcomplicating explanations**, especially when simpler, intuitive answers are more effective.
- We make sure not to **misapply ML techniques**, choosing the right tool for the problem rather than defaulting to complexity.
- We are careful not to **confuse correlation with causation**, especially when interpreting features or results without proper experimentation.
- We stay grounded by not **overstating model performance** and always considering **data quality** as a core factor in success.

By being clear, humble, and practically minded, we avoid these pitfalls and come across as thoughtful and well-prepared candidates.

If you want to learn even more from Yayun:

- Book 1 on 1 career guidance with her here: <https://calendly.com/your-friend-yayun/1on1>
- Follow her on LinkedIn: <https://www.linkedin.com/in/yayunjin/>

How To Properly Learn

In this section, we focus on the kind of preparation that truly sets us apart in machine learning interviews. Rather than relying on surface-level memorization, we learn how to build a deep, applied understanding that shines under follow-up questions and real-world discussion.

- We aim to **go beyond surface knowledge**, learning not just definitions but also how and why concepts work.
- We must understand **implementation details**, like the loss function in logistic regression or how feature importance is calculated in random forests.
- We should avoid vague “buzzword” answers and instead be honest if unsure—showing how we would reason through the problem is often more impressive than guessing.
- We connect **theory to practice**, drawing clear links between ML concepts and our own project experience to demonstrate applied understanding.
- We focus on **breadth with clarity**, going deep only where relevant, and always aim to explain ideas in a concise and structured manner to reflect true expertise.

If you want to learn even more from Yayun:

- Book 1 on 1 career guidance with her here: <https://calendly.com/your-friend-yayun/1on1>
- Follow her on LinkedIn: <https://www.linkedin.com/in/yayunjin/>

Different Roles, Different Focus

In this section, we explore how the emphasis on the four pillars of ML interview success shifts depending on the specific role we’re targeting. The course is designed to help us align our strengths with the expectations of different ML career paths.

- We learn that **ML infrastructure roles** prioritize software engineering and system design, as these roles focus on building scalable and reliable ML platforms.
- **Product-focused ML roles** value end-to-end system design and business impact, requiring us to connect our technical solutions directly to user outcomes.
- For **research-oriented roles**, a deep dive into ML theory and algorithms is essential, with an emphasis on innovation and pushing technical boundaries.
- We’ll identify our personal strengths and tailor our preparation to highlight the most relevant ones for our target role.
- We’ll also work on filling any skill gaps so we can enter interviews with greater confidence and a clear strategy.

If you want to learn even more from Yayun:

- Book 1 on 1 career guidance with her here: <https://calendly.com/your-friend-yayun/1on1>
- Follow her on LinkedIn: <https://www.linkedin.com/in/yayunjin/>

The 4 Pillars of ML Interview Success

In this segment of the course, we’re introduced to the core framework for succeeding in machine learning interviews: the four pillars of ML interview success. These pillars form the foundation of how we’re evaluated and what we should focus on during preparation.

- We need strong **software engineering foundations**, including clean coding, system design, and engineering best practices.
- We must demonstrate a solid understanding of **machine learning theory and algorithms**, knowing when and why to apply specific methods and models.
- We should be able to **design and implement end-to-end ML systems**, translating business problems into ML solutions while considering scalability, deployment, and data quality.
- We’re expected to show **business acumen**, aligning our technical decisions with product goals and user needs.
- Each interview round targets one or more of these pillars, and we’ll stand out by showing balanced strength across all four.

If you want to learn even more from Yayun:

- Book 1 on 1 career guidance with her here: <https://calendly.com/your-friend-yayun/1on1>
- Follow her on LinkedIn: <https://www.linkedin.com/in/yayunjin/>

Maximize Your Equity And Benefits In Tech [Part 22] - Healthcare And Miscellaneous Benefits

From picking the right medical plan to using hidden financial perks, there’s a lot you can do to stretch your benefits beyond equity. Here are the core points from the lesson:

- PPO, EPO, and HMO plans vary in flexibility and cost, with PPOs offering the most freedom and HMOs the lowest cost but most restrictions
- Understanding plan terms like premiums, deductibles, copays, and coinsurance helps you estimate total medical costs more accurately
- HSAs offer exceptional tax advantages and long-term growth potential, especially if you invest the funds and save receipts for future reimbursement
- FSAs are employer-based, use-it-or-lose-it accounts that are best used only when you know you’ll spend the funds during the year
- Tech workers may also have access to other valuable benefits like legal services, fertility support, wellness stipends, and insurance—but employer-provided life and disability coverage may not be enough if you truly need it

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 21] - Bottom Line

There are a few essential things to keep in mind when managing retirement accounts. Here are the core points from the lesson:

- 401(k)s are effective for automating savings and deferring taxes, especially in high tax brackets, and it's important to capture the employer match and invest contributions
- Pre-tax vs. Roth decisions aren’t one-size-fits-all, but choosing wisely can reduce your lifetime tax bill with the help of smart withdrawal strategies
- Mega backdoor Roths allow large tax-free contributions if your plan supports them, while backdoor Roths offer smaller contributions with more complexity and caution required

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 20] - Backdoor And Mega Backdoor Roths

Backdoor and Mega Backdoor Roth strategies offer powerful ways to boost tax-advantaged retirement savings for high earners. Here are the core points from the lesson:

- A Backdoor Roth involves making a non-deductible IRA contribution and quickly converting it to a Roth IRA, but you must avoid having pre-tax IRA balances or you'll face tax via the pro-rata rule
- Mega Backdoor Roths allow after-tax 401(k) contributions (beyond the regular limit) to be converted into Roth accounts, enabling up to \~$40K in additional Roth savings annually
- The ideal Mega Backdoor setup includes in-plan Roth conversions, which are often automatable and avoid tax on earnings during the transition
- Be cautious of contribution timing to avoid missing employer match benefits—either spread contributions evenly or ensure your plan supports a “true-up” feature

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 19] - Pre-Tax vs. Roth

Choosing between pre-tax and Roth 401(k) contributions can significantly impact your long-term tax outcomes. Here are the core points from the lesson:

- The net tax advantage between pre-tax and Roth depends on your current vs. future tax rates; Roth may be ideal if you're in a lower bracket now, but pre-tax offers flexibility for future low-tax Roth conversions
- Roth IRAs offer penalty-free access to contributions anytime, while Roth 401(k)s have stricter withdrawal rules, often treating withdrawals as a mix of contributions and earnings
- Pre-tax retirement accounts are subject to Required Minimum Distributions (RMDs) starting at age 73, which can force taxable income in retirement
- Doing Roth conversions during low-income years (e.g., early retirement) can reduce future RMD burdens and smooth your tax liability over time

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 18] - Liquidity And Workarounds

Accessing retirement funds early can be tricky, but there are some strategic exceptions. Here’s the core points from the lesson:

- Withdrawing from 401(k)s or pre-tax IRAs before age 59.5 typically triggers a 10% penalty, though exceptions exist for things like first-time home purchases, disability, or high medical costs
- Roth IRA contributions (not earnings or conversions) can be withdrawn at any time, penalty- and tax-free, while Roth conversions require a five-year wait before penalty-free access
- Strategies like the Roth conversion ladder or 72(t) withdrawals (Substantially Equal Periodic Payments) can help bridge the gap if retiring before 59.5
- If you leave your job at 55 or older, you can take penalty-free withdrawals from that employer’s 401(k), and possibly from other plans rolled into it

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 17] - 401(k) And IRA Basics

Understanding retirement accounts is essential for long-term financial planning. Here’s the core points from the lesson:

- 401(k)s allow automated payroll contributions (up to $23,500 in 2025 for those under 50), often include employer matching, and offer pre-tax or Roth contribution options
- Contributions reduce taxable income but are still subject to payroll taxes like Social Security and Medicare
- IRAs (individual retirement arrangements) are similar to 401(k)s but are personally managed, have lower contribution limits, and don’t include employer matching
- IRA contributions may be tax-deductible or Roth-eligible depending on your income, unlike 401(k)s which have no income-based restrictions for pre-tax contributions

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 16] - Stock Options Strategy

Stock option strategies can significantly affect your financial outcomes depending on timing, tax implications, and company events. Here's the core points from the lesson:

- Early exercise with an 83(b) election can offer long-term tax benefits, especially for qualified small business stock, but requires accepting the risk of losing the money invested
- For non-qualified stock options (NSOs), exercising and holding is risky due to upfront ordinary income tax that isn't offset if the stock later declines
- Strategies like exercising and immediately selling (or cashless exercise) can reduce risk and lock in gains, especially around liquidity events like IPOs
- AMT planning for incentive stock options (ISOs) includes spreading exercises across tax years or alternating years of exercise and sale to manage tax impact and recover AMT credits
- Exercising ISOs early in the year offers flexibility to sell later in the year if the stock drops (avoiding AMT) or hold into the next year for favorable capital gains treatment

For more on why you might want to exercise your ISOs early in the year, [click here](https://adastrafp.com/exercising-isos-early-in-year/). For my AMT Calculator (for informational purposes only, not tax advice), [click here](https://adastrafp.com/amt-calculator/).

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 15] - Alternative Minimum Tax Basics

Alternative Minimum Tax (AMT) can create surprise tax liabilities, especially when exercising incentive stock options. Here's the core points from the lesson:

- AMT is a parallel tax system with fewer deductions, aimed at ensuring high earners pay baseline taxes, and it most often affects those exercising ISOs below market value
- Unlike the progressive regular tax system, AMT uses flat rates (26% or 28%) and doesn’t allow deductions like standard or state/local taxes, leading to potentially higher taxes
- The difference between ISO strike price and market value counts as AMT income, which may trigger a large tax bill even if the shares aren't sold
- Any excess AMT paid over regular tax becomes a credit that can offset future tax liabilities, but recovering it depends on your future income and tax situation

[Check out my AMT Calculator here](https://adastrafp.com/amt-calculator/) (for informational purposes only, not tax advice.)

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 14] - Stock Option Special Tax Considerations

When working at an early-stage startup, certain tax strategies can unlock major financial advantages—if you plan ahead. Here are the core points from the lesson:

- Qualified Small Business Stock (QSBS) can allow up to $10 million or 10x your basis in tax-free capital gains if you meet specific conditions, like holding actual shares for five years and your company having under $50M in assets at grant
- Early exercise and filing an 83(b) election can start the QSBS clock early and lock in low tax values, but they come with financial commitment and risk if you leave before fully vesting
- The 83(b) election must be filed within 30 days of exercising options and doesn't accelerate the two-year holding clock required for qualified ISOs
- Only $100K worth of ISOs can vest annually for favorable tax treatment—going above that limit risks converting some to NSOs with different tax implications

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 13] - Stock Option Basics

Stock options offer exciting upside but come with layers of tax complexity depending on type and timing. Here are the core points from the lesson:

- Private company stock options come in two forms: incentive stock options (ISOs) and non-qualified stock options (NSOs), each with different tax rules
- NSOs trigger ordinary income tax at exercise on the spread between strike price and fair market value, with additional capital gains tax upon sale
- ISOs can offer better tax treatment if held for 2 years from grant and 1 year from exercise, avoiding ordinary income tax but potentially triggering alternative minimum tax (AMT)
- Selling ISOs in the same year as exercising can help avoid AMT, but splitting the tax years may result in both AMT and ordinary income tax, creating a worst-case scenario

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 12] - RSUs (Private Company Equity)

Private company RSUs can be rewarding but come with unique structures, tax challenges, and limited liquidity options. Here are the core points from the lesson:

- Most private RSUs are double-trigger, requiring both time-based vesting and a liquidity event, unlike public RSUs which are typically single-trigger
- Single-trigger RSUs in private companies can create tax issues if you owe taxes on illiquid shares you can’t sell
- Liquidity events like tender offers, IPOs, direct listings, or acquisitions are when real decision-making occurs, though each comes with restrictions like lock-up periods or partial sell limits
- IPOs typically involve a six-month lock-up period, while direct listings may allow earlier sales and fewer constraints
- It’s essential to plan for taxes—sell-to-cover elections may not fully satisfy tax liability due to lower default withholding rates on equity compensation

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 11] - Insider Trading Considerations

Insider trading rules can create real constraints on when and how you can sell company stock, especially for those with access to sensitive information. Here are the core points from the lesson:

- Insider trading laws prohibit trading on material non-public information, and companies often enforce blackout periods to limit employee risk
- Executives and directors face stricter requirements, including preclearance, holding periods, and detailed SEC reporting (e.g., Forms 4, 144)
- A 10b5-1 plan allows for pre-scheduled trades made while not in possession of inside info, offering a compliant path to selling equity under constraints

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

Maximize Your Equity And Benefits In Tech [Part 10] - Strategy (ESPP)

ESPPs can offer significant value, but deciding when to sell requires more nuance than it may seem at first glance. Here are the core points from the lesson:

- If there’s no holding period requirement, selling immediately after purchase can yield guaranteed gains, especially with discounts and lookback provisions
- Holding ESPP shares introduces market risk and complexity, and your decision should reflect whether you’d buy the stock outright if given the equivalent in cash
- A holding period aligned with qualified disposition rules may offer better tax treatment—but not always; in some cases, a disqualifying disposition results in lower overall tax
- When stock declines during the offering but rebounds before sale, the tax owed under a qualified disposition may be higher due to how ordinary income is calculated from the offering price rather than purchase price

Next steps with Andy:

- [Connect with Andy on LinkedIn](https://www.linkedin.com/in/andymoranio)
- [Leave feedback and/or sign up for Andy’s newsletter](https://subscribepage.io/taroequitycourse)
- [Schedule a consultation](http://adastrafp.com/contact-us/)

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.