Senior Backend Engineer — Payments Platform
senior · version v1-dowLDG
b30c1d01-ff1a-48a7-8626-cbbc74a67f94
Competencies
weights sum to 1.00| Name | ID | Weight | Definition |
|---|---|---|---|
| Financial System Design & Correctness | financial_system_design | 0.35 | Design idempotent state machines for payment lifecycles with guaranteed consistency, recovery paths for all states, and double-entry accounting principles. Demonstrated ability to reason about money movement correctness, reconciliation logic, and settlement edge cases. |
| Distributed Systems Fundamentals | distributed_systems_mastery | 0.25 | Deep understanding of consensus, ordering guarantees, retry semantics, and exactly-once delivery constraints. Can architect solutions that handle failures without money-related data loss or duplication. |
| Postgres Transactional Schema Design | postgres_transactional_design | 0.20 | Design and optimize schemas for high-throughput transactional workloads with appropriate isolation levels, locking strategies, and query patterns. Experience tuning Postgres for payment-scale throughput and correctness. |
| End-to-End Domain Ownership | end_to_end_ownership | 0.15 | Own critical payment system components from design through production operations, including on-call responsibility, incident postmortems, and preventive architecture improvements. Build reliable systems that reduce customer-impacting incidents. |
| Production Systems Maturity | production_systems_maturity | 0.05 | 5+ years shipping backend systems at scale with strong observability, testing, and operational discipline. Comfortable navigating tradeoffs between correctness, performance, and compliance in financial infrastructure. |
Scoring Weights
Adjust how much each competency contributes to the final score. Changes apply to all future evaluations for this job spec.
financial_system_design
35%0.35
distributed_systems_mastery
25%0.25
postgres_transactional_design
20%0.20
end_to_end_ownership
15%0.15
production_systems_maturity
5%0.05
Total weight: 1.00 ✓ balanced
Interview questions
AI-generated from the JD · auto-published · edit anytime3 currently · candidate sees this many
Behavioral round (Round 02)
Voice Q&A · pre-generated from the JD · edit anytime4 prompts · Cal walks through each in order during Round 02
Live performance
Aggregated from candidates who took this job spec.
Interviews
1
0 completed
Avg score
—
out of 100
Completion
0%
0 of 1
Avg score per competency
Financial System Design & Correctnessweight 0.350.00n=1
Distributed Systems Fundamentalsweight 0.250.00n=1
Must-haves
- required5+ years building backend systems in production with Python
- requiredStrong SQL expertise; demonstrated schema design for high-throughput transactional Postgres workloads
- requiredDeep understanding of distributed systems concepts (consensus, ordering, idempotency, exactly-once semantics)
- requiredTrack record of owning production incidents, writing postmortems, and implementing preventive solutions