Technical leadership

Question 1

You want to propose splitting the billing code out of the main monolith. Before writing a long design doc, what should you do first?

Accepted Answer

Talk with billing's owners and its callers to learn their real pain points and limits.

Question 2

Your design doc for a new job queue is twelve pages. Reviewers keep missing the key tradeoff. What change helps most?

Accepted Answer

Open with a one-page summary: the problem, the decision needed, and the main tradeoff.

Question 3

A design doc you are reviewing lists only the chosen approach. What is the most useful request to make of the author?

Accepted Answer

List the alternatives considered and why each was rejected.

Question 4

Three teams each want to build their own feature flag system. You think one shared approach is better. What is the strongest first move?

Accepted Answer

Write a short doc comparing the three teams' needs and ask each team to review it.

Question 5

You set a direction that new services use one standard logging library. Six months later, half of new services still do not. What do you check first?

Accepted Answer

Whether the library is hard to adopt or missing what those teams need.

Question 6

You are writing a technical vision for your area for the next two years. Which approach makes it most useful?

Accepted Answer

Tie it to problems teams feel today and name the first steps toward the goal.

Question 7

Your design doc has been open for comments for three weeks. Comments have stopped but no one has approved it. What do you do?

Accepted Answer

Name the approvers, set a decision date, and say what happens if no one objects by then.

Question 8

A peer asks you to review their doc for a cache layer. You think the whole approach is wrong. How do you give that feedback?

Accepted Answer

Talk with them directly first and explain the concern and its evidence.

Question 9

In a design review, one senior engineer strongly objects to your chosen database. Others are quiet. What do you do in the meeting?

Accepted Answer

Ask them for the specific failure they expect, then ask the quiet reviewers for their view.

Question 10

You run design reviews for your group. The same two people dominate every session. What change helps most?

Accepted Answer

Collect written comments first and use the meeting for the open ones.

Question 11

After a long review, the team is split between two reasonable designs. Both meet the requirements. Who should decide, and how?

Accepted Answer

The named owner picks one, writes down why, and the team commits.

Question 12

A junior engineer presents a design with a real flaw. Several reviewers start piling on. You are the senior in the room. What do you do?

Accepted Answer

Name the flaw once, clearly, and steer the group toward fixes.

Question 13

You disagree with a design your team chose after a fair review. You were overruled. What should you do now?

Accepted Answer

Commit to it and help it succeed, noting what evidence would reopen it.

Question 14

A reviewer leaves forty small style comments on a design doc and none on the risky data migration section. What do you do as the review lead?

Accepted Answer

Ask reviewers to focus on the migration section, where the real risk is.

Question 15

Your team skips design review for small changes. One small change to a shared retry library caused an outage. What do you change?

Accepted Answer

Require review based on how many callers a change affects, not its size.

Question 16

During review, someone raises a concern you have not thought about and cannot answer. What is the best response?

Accepted Answer

Say you do not know yet, log it as an open question, and follow up.

Question 17

You must choose a message broker for a new system. You lack data on future load. The team wants another month of benchmarking. What do you do?

Accepted Answer

Pick the easier one to replace, record the load assumption, and set a review trigger.

Question 18

A decision was made two years ago to use a custom build tool. New people keep asking why. What is the most useful thing to do?

Accepted Answer

Write a short decision record with the context and reasons, linked from the repo.

Question 19

You chose a schema design last quarter. New usage data shows one of its assumptions was wrong. What do you do?

Accepted Answer

Reopen the decision openly, share the data, and propose a path.

Question 20

Your team debates for weeks whether to use one framework or another. Both would work. What is the leader's job here?

Accepted Answer

Set a short deadline, list the criteria, and make the call.

Question 21

You need to decide whether to adopt a new language for one service. The choice would be hard to undo. How should you approach it?

Accepted Answer

Get input from the teams who would maintain it, and trial it on a contained piece first.

Question 22

A teammate asks you to approve a choice of serialization format. You have a mild preference but no strong reason. What do you do?

Accepted Answer

Let them decide, since they own the work and either format works.

Question 23

You decided to delay a database upgrade for one quarter. How should you record that decision?

Accepted Answer

Note the reason, the risk accepted, and when it comes back up.

Question 24

An outage forces a fast call: roll back a release or push a fix forward. You are the senior on the call. Data is incomplete. What do you do?

Accepted Answer

Roll back now to the known good state, then work on the fix.

Question 25

You lead a two-quarter project to split the orders module out of the monolith. How should you sequence the work?

Accepted Answer

Ship one thin slice end to end, such as a single read path, then expand.

Question 26

Midway through a project, product asks for two new features. Your team cannot deliver them and hit the date. What do you do?

Accepted Answer

Show product which scope or date moves if the features come in.

Question 27

A director asks your team to take on a new internal tool. You already have two committed projects. What is the best response?

Accepted Answer

Say what would be dropped or delayed, and ask which outcome matters most.

Question 28

Your project has a fixed launch date tied to a partner event. Work is behind. What should you cut first?

Accepted Answer

Nice-to-have features, keeping the core flow and its reliability.

Question 29

You are planning a multi-quarter rewrite of the search indexer. How do you define milestones?

Accepted Answer

As points where callers get real value.

Question 30

Your team has ten requests from other teams this quarter and room for four. How do you choose?

Accepted Answer

Rank them by impact on the team's goals, publish the list, and explain the cuts.

Question 31

An engineer proposes building a general plugin system for a feature only one customer needs. What do you suggest?

Accepted Answer

Build the specific feature, and generalize when a second need appears.

Question 32

A stakeholder asks for an estimate on a vague project in a meeting. What is the best answer?

Accepted Answer

A wide range, the main unknowns, and a tighter number after a short spike.

Question 33

The continuous integration (CI) test suite has many flaky tests. Engineers rerun builds several times a day. How do you make the case to fix it?

Accepted Answer

Measure hours lost to reruns and blocked merges, and pair that cost with a plan.

Question 34

Your team wants to spend a full quarter on tech debt with no feature work. Product objects. What approach usually works best?

Accepted Answer

Tie specific debt items to outcomes product cares about, and blend them into plans.

Question 35

You have a list of thirty tech debt items. Which do you tackle first?

Accepted Answer

The ones that slow the team's most frequent work.

Question 36

An engineer proposes a full rewrite of the payments service because the code is hard to read. What do you ask first?

Accepted Answer

What problems the code causes today, and whether refactors would fix them.

Question 37

A rewrite proposal for an old reporting system has support. What condition matters most before approving it?

Accepted Answer

A plan to run old and new side by side and move users gradually.

Question 38

Leadership asks why a feature took three times the estimate. The cause was an old, tangled module. How do you explain it?

Accepted Answer

Show how the module slowed this work, its cost on upcoming work, and a fix.

Question 39

You inherit a service with no tests. The team keeps shipping bugs in it. Where do you start?

Accepted Answer

Test the code paths that change most and where bugs appeared.

Question 40

The team set aside 20 percent of time for debt, but it is always the first thing cut when deadlines loom. What do you do?

Accepted Answer

Pick a few debt items with owners and goals, tracked like projects.

Question 41

Forty teams depend on a shared HTTP client library. You need them to move to a new major version. What is the most effective approach?

Accepted Answer

Ship an automated upgrade tool, move a few teams first, and track progress openly.

Question 42

A migration to a new config system is 90 percent done. The last five teams keep delaying. What do you do?

Accepted Answer

Meet each team, learn its blocker, and offer help or a firm dated plan.

Question 43

You are splitting a monolith. Teams worry that moving their code will break things. What reduces that fear most?

Accepted Answer

A shadow mode that runs both paths and compares results.

Question 44

Your shared library has two hundred callers. You need to remove a deprecated function. What is the first step?

Accepted Answer

Find every caller with code search or usage data.

Question 45

Halfway through a migration, the new system shows a performance problem under one team's workload. What do you do?

Accepted Answer

Pause that team's move, fix the problem, and keep others moving.

Question 46

Leadership asks when the monolith split will be done. Progress is real but uneven. What do you report?

Accepted Answer

What has moved, what remains, the main risks, and a range for the finish.

Question 47

Two teams must coordinate a database migration. Each assumes the other is doing the cutover script. You notice this a week out. What do you do?

Accepted Answer

Get both leads together today and name one owner for the script.

Question 48

A migration plan needs every team to do a small change. Teams have no capacity this quarter. What helps most?

Accepted Answer

Send each team a ready pull request and ask only for review.

Question 49

After a migration finishes, the old system is still running because a few internal tools read from it. What should you do?

Accepted Answer

Find those tools and move them, since shutdown is part of the project.

Question 50

Code reviews on your team take three days on average. Engineers are frustrated. What change helps most?

Accepted Answer

Set a review response target, keep changes small, and show review load on the board.

Question 51

You keep leaving the same review comment about missing input checks. What is the better long-term fix?

Accepted Answer

Add a lint rule or shared helper so the check no longer depends on memory.

Question 52

A strong engineer on your team ships fast but often skips tests, and others start copying that habit. What do you do?

Accepted Answer

Talk to them directly about the effect on the team and agree on what testing is expected.

Question 53

Every few months someone causes an outage by changing production config by hand. What do you push for?

Accepted Answer

Config changes made in reviewed code, with checks before production.

Question 54

You want to raise quality standards across five teams. You have no authority over them. What is the best start?

Accepted Answer

Fix one painful quality problem with a shared tool that teams can adopt easily.

Question 55

Your team relies on one engineer who manually checks each release before it ships. They are going on leave. What should you have done earlier?

Accepted Answer

Turned their manual checks into automated tests and a written release checklist.

Question 56

Reviewers on your team approve almost everything with no comments. Bugs are slipping through. What helps most?

Accepted Answer

Walk through a few merged changes as a team and discuss what review should catch.

Question 57

The flaky test problem is getting worse. You have one engineer for two weeks. What is the highest-value use?

Accepted Answer

Tooling that detects flaky tests, quarantines them, and assigns each an owner.

Question 58

A team asks you to write a style guide for the codebase. Most style debates are about formatting. What do you do?

Accepted Answer

Adopt an automatic formatter, and write a short guide only for what tools cannot check.

Question 59

A junior engineer has been stuck on the same task for a week without asking for help. What do you do first?

Accepted Answer

Sit with them, have them walk through what they tried, and find the next step together.

Question 60

After helping the stuck junior engineer, how do you stop it from happening again?

Accepted Answer

Agree on a time limit for being stuck before asking, plus a short regular check-in.

Question 61

You want to grow a mid-level engineer toward senior. What is the most effective step?

Accepted Answer

Give them a project with real ambiguity to own, and coach rather than direct.

Question 62

You delegated a design to a teammate. Their design is workable but not how you would do it. What do you do?

Accepted Answer

Let them proceed, offer your view as one option, and push back only on real risks.

Question 63

You are on an interview loop. Another interviewer says a candidate was not a culture fit but gives no examples. What do you do in the debrief?

Accepted Answer

Ask what specific behavior they saw, and weigh only evidence tied to the role.

Question 64

You are asked to level a candidate. They solved the coding problem well but showed little sense of tradeoffs in design. What level fits best?

Accepted Answer

The level their design evidence supports, with that evidence written down.