Sr. Staff Engineer - Payments & Commerce Platform

About the Role:

We’re building a global commerce platform to power $1T+ in annual transactions for millions of SMEs. We want our Principal Enggs to be the technical force‑multiplier who sets the domain modelling, architecture, raises the reliability bar, and multiplies team effectiveness. You’ll steward our core commerce models—subscriptions, payments , Catalog, Pricing, Inventory, fulfillment, reconciliation , tax —and the services around them, ensuring correctness by design, auditability, and delightful performance at scale. This is an IC role with org‑level influence (no direct reports), focused on designing systems, shaping standards, and growing engineers.

Tech Stack:
Backend: Go, ConnectRPC
Databases: MongoDB, Firestore, ClickHouse
Cloud: GCP (GKE), Pub/Sub, Redis, OpenTelemetry

What You’ll Do:

Architect and ship multi‑tenant, planet‑scale services (checkout, subscriptions, payments orchestration, invoicing, tax hooks) with clear domain boundaries (DDD) and hard SLOs

Be the custodian of API & schema design: own protobuf/ConnectRPC conventions, versioning policy, deprecation playbooks, and Buf breaking‑change checks—so our contracts stand the test of time

Guarantee resilience & availability of core payment paths: timeouts, retries with jitter, circuit breakers, idempotency keys, outbox/Saga patterns, hedged requests, and graceful degradation

Ensure complete auditability: append‑only double‑entry ledger, immutable event streams, trace‑linked entities (OTel trace/span IDs), tamper‑evident trails, and reconciliations that tie out to the cent

Own error boundaries end‑to‑end: enumerate failure domains (PSP, network, data, concurrency, quota, browser, device); design uniform error contracts; implement compensations/backfills and automated replay

Keep track of every deployed thing: services, workers, triggers, cron, subscriptions—own the service catalog and scorecards (owners, SLOs, runbooks, PDBs, HPA/VPA, budgets, quotas, timeouts)

Configuration & limits stewardship: enforce sane defaults across GKE, Pub/Sub, Redis, Firestore/Mongo, ClickHouse—connection pools, ack deadlines, batch sizes, TTLs, memory/FD limits, and GCP quotas

Observability as a product: pervasive OpenTelemetry, RED/USE metrics, exemplars, trace sampling, SLO dashboards, and alerting that wakes humans only for user‑impacting issues

Production excellence: canary/blue‑green rollouts, automated rollbacks, chaos drills, DR playbooks (RPO/RTO), multi‑region failover strategies, and incident command on rotation

Security & compliance by design: PCI scope minimization, tokenization/vaulting, secrets/KMS hygiene, data retention/archival, and privacy controls—embed checks in CI/CD

Developer acceleration: pave golden paths (service templates, ADR/RFC process, linting/formatting, contract tests, ephemeral envs, load/perf harnesses) to make the right thing the easy thing

What You’ll Lead:

Core domain evolution: orchestration → ledger → reconciliation flows with crisp invariants and consistency guarantees (read‑your‑writes where needed, eventual where appropriate)

Reliability strategy: SLIs/SLOs, error budgets, capacity planning, cost/FinOps guardrails, multi‑region posture, and DR exercises

API & data governance: canonical models, schema lifecycle (compatibility matrix, migrations), data lifecycle (retention, archival, compliance)

Practice leadership for HighLevel: design reviews, postmortems, technical strategy, coding standards, and mentorship across teams—raise the bar for the org

Hiring & team growth: help us hire, scale, and train the right team; shape interview loops, rubrics, onboarding, and ongoing learning (brown bags, reviews, pair design)

Cross‑functional partnership: collaborate with Product/Marketing/Support to translate platform capabilities and constraints into roadmaps, GTM narratives, and reliable customer outcomes

Risk & roadmap: maintain a technical risk register, make build‑vs‑buy calls, and propose simplifications or deprecations that meaningfully reduce complexity and MTTR

Minimum Qualifications:

10+ years building and operating backend systems (at least 5+ years in Go), with 2–3+ years acting as a Staff/Principal‑level IC or Tech Lead for critical paths

Deep proficiency with protobuf + ConnectRPC/gRPC and API lifecycle management (versioning, compatibility, contract testing, Buf)

Distributed systems fundamentals: idempotency, exactly‑once‑ish via dedupe/outbox, ordering, consensus basics, backpressure, concurrency control

Event‑driven architectures on GCP (Pub/Sub), plus Redis for fast paths; strong schema design in MongoDB/Firestore and analytics/reporting patterns on ClickHouse

Kubernetes/GKE operations at scale: autoscaling (HPA/VPA), PDBs, resource limits/requests, multi‑region topologies, CI/CD, canary/blue‑green

Reliability engineering: SLIs/SLOs, error budgets, capacity & load testing, incident management, DR/BCP

Security & compliance: secrets/KMS best practices, PCI basics (scope reduction, key rotation), and data governance (retention/archival)

Testing discipline: unit, integration, contract, property‑based, performance; test data management and deterministic environments

Frontend collaboration: solid understanding of Vue.js + TanStack Query to shape clean API surfaces and performance budgets across the boundary

Exceptional technical writing & communication: design docs, ADRs/RFCs, postmortems, and stakeholder updates

Nice to Have:

Hands‑on integrations with major PSPs/local rails (e.g., UPI, wallets, BNPL, cards/3DS2) and reconciliation at scale

Experience with active‑active or multi‑region designs; chaos engineering; traffic management

Observability leadership with OpenTelemetry at org scale (tail‑based sampling, exemplars)

FinOps experience: cost baselining, quotas, budget alarms, and workload right‑sizing

Familiarity with regulatory frameworks (PCI DSS, SOC 2/ISO 27001) and privacy laws relevant to our markets