QA Automation Engineer / SDET (Remote - Central & South America)

QA Automation Engineer – Contract Role

Lattice Payment Orchestration

About Lattice

Every second, businesses lose money to broken payment infrastructure. Banks and fintechs waste engineers on fragile integrations, payment startups burn through PSP vendor lock-in, and enterprises can't route intelligently across providers.

Lattice is fixing that. We're building the payment orchestration layer that lets companies connect once, integrate with any PSP (Stripe, Klarna, PayPal, ACH, crypto, you name it), and route transactions intelligently based on cost, performance, and compliance. Think Twilio for payments.

We're pre-seed, but we're already processing millions in transaction volume. Our customers span B2B SaaS, marketplaces, fintechs, and crypto platforms. They trust us because we obsess over reliability, compliance, and speed.

Why join now?

You're solving a 10-figure market problem with a small team that ships fast

Every test you write prevents millions in fraud, chargebacks, or compliance violations

You'll own QA at a company that will IPO—get in early

Work on payment infrastructure used by platforms you probably know

Tech Stack: TypeScript/JavaScript (Vitest, Playwright, K6), GCP serverless, PostgreSQL, BigQuery, GitHub Actions

Compliance: PCI DSS 4.0, SOC 2

The Role

We're seeking an experienced QA Automation Engineer to strengthen our testing practices and release confidence as we scale from pre-seed to production. You'll build automated testing frameworks and pipelines for a payment infrastructure platform handling millions in transaction volume.

This is a remote contract position open to engineers in Latin America.

Responsibilities

Write and maintain API/integration, UI/E2E, load, and security test suites using Vitest, Playwright, and K6

Build test infrastructure on GCP (Cloud Run, BigQuery, Firestore)—GitHub Actions CI/CD pipelines, test data generation (Faker.js), and observability

Design compliance-focused tests covering PCI DSS 4.0 and SOC 2 controls (Cloud Armor WAF, JWT/Auth0 validation, webhook signing verification)

Test payment flows end-to-end: PSP integrations (Stripe, Klarna, Braintree, NMI, ACH), transaction routing, webhook handling, reconciliation, and eventual consistency patterns

Build data pipeline validation using SQL, BigQuery, and custom metrics collection; integrate Allure test reporting

Collaborate with a small engineering team (2–4 people) to maintain high coverage, catch production issues early, and optimize multi-tenant architecture testing

Contribute to test infrastructure automation (Bash/shell scripting, Workload Identity Federation) and Slack notifications for test results

Document test cases, known issues, QA processes, and domain-specific testing patterns for scaling

What We're Looking For

Required Experience:

3+ years of QA automation (TypeScript/JavaScript strongly preferred)

Strong hands-on experience with Playwright (E2E/UI testing) and Vitest (API/integration testing)

Proficiency with Node.js (v24+) and TypeScript (ESM modules, type safety)

SQL proficiency for database-level testing and validation (PostgreSQL, BigQuery)

Experience with GitHub Actions or similar CI/CD pipelines

Understanding of REST APIs, webhooks, and integration testing patterns

Written and spoken English (team communication and documentation)

Nice to Have:

Experience with K6 for load & performance testing

Familiarity with Allure advanced test reporting

Knowledge of payment systems, fintech, or PCI compliance

GCP experience (Cloud Run, BigQuery, Firestore, Cloud Armor)

Load testing, security testing (WAF), or data pipeline validation

JWT, Auth0, HMAC signing, or webhook verification

Experience with contract/freelance roles and self-direction

Faker.js or test data generation libraries

Qualities:

Detail-oriented and proactive in catching edge cases

Comfortable with ambiguity (pre-seed startup)

Strong async communication for distributed team

Ownership mindset—you test what matters and flag risks early

What We Offer

Competitive rate $2,300 - $3,000 USD per month (dependent on experience and technical assessment). This is a 9–12 month independent contractor agreement with potential for extension.

Flexible schedule with clear sprint planning

Impact-driven work—your tests directly affect millions in transaction volume

Learning opportunity—modern payment systems, GCP, compliance frameworks

Small team environment—direct collaboration with founders and engineers

Remote-first culture across distributed team

Technical Details You Should Know

Testing Frameworks: Vitest (API/unit), Playwright (E2E/UI), K6 (load & performance)

Language: TypeScript/JavaScript (Node.js v24+, ESM modules), strong type safety with Zod

GCP Infrastructure: Cloud Run (serverless backends), BigQuery (analytics), Firestore, Global Load Balancer, Cloud Armor (WAF)

Databases: PostgreSQL (transactional), BigQuery (data pipeline validation)

CI/CD: GitHub Actions with Depot for self-hosted runners

Security & Auth: JWT (jose library), Auth0, Cloud IAP, HMAC webhook signing

PSP Integrations: Stripe, Klarna, Braintree, NMI, ACH—webhook verification, eventual consistency, multi-tenant isolation

Test Scope:

API/Integration tests (Vitest) against payment orchestration endpoints

E2E/UI tests (Playwright) for merchant dashboards and integrator portals

Load & performance tests (K6) for transaction throughput and latency SLOs

Security tests (Cloud Armor WAF, JWT validation, HMAC verification)

Data validation (SQL/BigQuery) for settlement reconciliation and audit trails

How to Apply

Submit:

Resume/CV (emphasizing QA automation projects)

Portfolio or GitHub (test framework examples, automation scripts)

Brief cover letter explaining interest in fintech/payment testing and availability

Questions?

We're happy to discuss scope, rates, and start date flexibly. Reach out with questions about the role or Lattice.

About You: You're an experienced QA engineer looking for a high-impact contract role at a fintech startup. You build reliable, maintainable test frameworks and take pride in shipping quality software. You thrive in small teams and don't shy away from learning new stacks.

Start Date: ASAP (flexible ramp-in period available)

Lattice is an equal opportunity employer committed to building diverse teams.