Backend Engineer
Amazon · Mid-level
Recommended next: your first attempt
Do the Online assessment: coding round.
A complete first attempt shows where you stand before any narrow practice starts.
The loop
Pick a round to see what it asks of you and where you stand on it.
Online assessment: coding
Practice the assessed 90-minute coding stage: complete two problems and protect time for independent verification.
Coding · 90 minSet up this round
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What strong sounds like
- Establish an approach for each problem and avoid consuming the whole window on one.
- Write complete, coherent code for both tasks rather than pseudocode fragments.
- Check empty, minimal and adversarial inputs appropriate to each task.
- Manually trace both implementations and explain time and space costs.
Expect to be pushed on
How does the algorithm behave at the largest input size?
Which boundary would invalidate the current approach?
Shapes of problem you may get
- First algorithmic problem with implementation and complexity
- Second independent problem with boundary-case verification
How to prepare
- 01
Select two-pass coding tactics
Decide how you will divide the 90 minutes after reading both problems. Set a stopping rule for a difficult problem and reserve a fixed final check for each solution.
Amazon reports two coding questions in 90 minutes. A time decision protects the second submission and supports the stated verification bar.
Company researchAmazon SDE II Interview PrepAmazon SDE II Online Assessment Prep
- 02
Prepare an edge-case checklist
Write a short checklist covering empty, minimal, duplicate, boundary, invalid, and adversarial inputs. For each problem, identify which items apply before writing code.
A first attempt takes the full 90 minutes.
What this loop tests
Amazon SDE II preparation starts with the online assessment, then four 55-minute loop interviews. Build fluency in algorithms, maintainable object-oriented code, and scalable service design. Leadership Principles are assessed throughout: bring specific decisions, customer impact, and lessons that withstand repeated probing. This plan pairs technical depth with ownership evidence and includes the assessment’s two-problem coding timebox.
They reward
- Customer consequences
- Maintainable working logic
- Ownership supported by decisions
- Learning that changes mechanisms
What to avoid
- Do not chase a difficult optimization while the second task is untouched.
- Do not confuse example correctness with general correctness.
- Do not substitute principle names for evidence.
- Do not stop after only explaining the optimal idea.
- Do not enumerate design patterns instead of writing the flow.
How sure we are
Worth redoing if you hear something from the recruiter that contradicts this.
Attempts
Every session saved against this target, newest first. Standings live on the round cards.
Online assessment: coding, Coding and problem solving, Maintainable code and object design, System design and customer trade-offs, and Leadership Principles and Bar Raiser have no attempts yet.