Senior Software Engineer, Fullstack

CodinGame SA; Mexico; Hybrid; MXN 600,000 - 1,000,000; Full time

Job summary

CodinGame SA in Mexico is seeking a Senior Software Engineer to help shape the future of technical interviewing and assessment across CoderPad. This is a fullstack role spanning backend, frontend, and AI-powered system design.

You will ship user-facing features, improve real-time AI experiences, and contribute to reliable, observable production systems.

The role emphasizes remote collaboration across time zones, strong code reviews, and ownership of long-term technical health.

Qualifications

• Senior-level experience shipping production software end-to-end in a fullstack capacity.
• Strong backend skills in at least one modern language + frontend experience with a component-based framework.
• Experience with AI agentic development workflows and AI-assisted development.
• Experience building AI-enabled production systems with LLM APIs, prompt design, streaming, and cost-aware engineering.
• Proven code-review leadership and mentoring peers.

Responsibilities

• Build and ship fullstack product features across candidate and recruiter experiences.
• Improve real-time AI-powered experiences, including model orchestration and streaming UX.
• Contribute to systems integrating multiple LLM providers with latency and observability considerations.
• Develop deterministic internal tooling to enable safe, repeatable engineering work.
• Collaborate with product, design, and platform teams to take problems from definition to production.

Skills

Fullstack experience

Backend engineering

Frontend engineering

AI systems experience

Code review mentoring

On-call / incident response

Remote collaboration

Tools

Ruby on Rails

Java

Node/TypeScript

React

PostgreSQL

GraphQL

Redis/Sidekiq

Datadog

Job description

Role Summary

We are hiring a Senior Software Engineer to help build the future of technical interviewing and assessment across CoderPad.

This is a fullstack role for someone who can move across backend services, frontend product surfaces, and AI-powered system design. You will work on user-facing features, production infrastructure, and internal engineering workflows where coding agents and AI-assisted development are part of normal day-to-day execution.

This role is remote from Latin America.

What You Will Work On

• Build and ship fullstack product features across candidate and recruiter experiences, from API and data model design to frontend implementation.
• Improve real-time AI-powered experiences used in interviews and assessments, including model orchestration, streaming UX, tool/function-calling patterns, and reliability.
• Contribute to systems that integrate multiple LLM providers and require pragmatic handling of latency, cost, observability, and non-deterministic behavior.
• Develop and improve deterministic internal tooling that helps engineers and agents execute work safely, repeatably, and with strong audibility.
• Partner across product, design, and platform teams to take ambiguous problems from definition to production rollout.
• Lead and mentor through code review, using reviews as both a quality gate and a coaching channel for less-experienced engineers.
• Plan and deliver technical debt, architecture, and observability initiatives that improve long-term system maintainability.
• Participate in on-call operations and drive runbook, reliability, and incident follow-up improvements.

Requirements

• Senior-level experience shipping production software end-to-end in a fullstack capacity.
• Strong backend engineering skills in at least one modern language and ecosystem, plus practical frontend experience with a component-based framework.
• Proven ability to pick up unfamiliar stacks quickly and deliver in mixed-technology environments.
• Hands-on experience with agentic development workflows (for example: Cursor, Claude Code, Codex, or equivalent), including good judgment on delegation, context scoping, and review of AI-generated code.
• Experience building production systems that use AI, such as LLM API integrations, prompt and context design, streaming responses, tool/function calling, and token or cost-aware engineering.
• Significant contribution to code review, with evidence of raising code quality and mentoring peers through the review process.
• Experience identifying and reducing technical debt, and contributing to architecture planning and documentation.
• Proven ownership of production system health through monitoring/alerting improvements, incident response, and operational follow-through.
• Experience partnering with product and technical leads on backlog preparation, scoping, sizing, and delivery planning.
• Strong engineering fundamentals in testing, observability, debugging, and safe incremental delivery.
• Clear written communication and collaborative ownership mindset in remote teams.

Desired Stack

You are not expected to know all of these technologies. Relevant equivalent experience is absolutely welcome.

• Backend surfaces include Ruby on Rails, Java services, and Node/TypeScript services.
• Frontend surfaces include React + TypeScript applications and shared web platform tooling.
• AI systems include integrations across Anthropic, OpenAI, Gemini, Llama, and Mistral families, with streaming and tool-calling capabilities.
• Platform and infrastructure include PostgreSQL, GraphQL, Redis/Sidekiq, Firebase Realtime Database, Datadog, LaunchDarkly, GitLab CI, cloud services (AWS and GCP), and containerized execution environments.
• Internal engineering workflows include Python-based deterministic CLI tooling and AI-agent skills that support repeatable development operations.

How We Work

• Remote-first collaboration across time zones with a strong written culture.
• AI tooling is an expectation and treated as part of the engineering toolbox.
• Small, reviewable changes with high-quality code review and shared ownership of outcomes.
• Pragmatic architecture decisions focused on reliability, maintainability, and user impact.
• Documentation and operational clarity are part of shipping, not afterthoughts.
• Senior ICs influence technical roadmap direction beyond their immediate delivery scope.
• Operational ownership matters: we value engineers who improve on-call practices and close the loop after incidents.

Logistics

• Required overlap window with core team: Pacific 7:00 - 16:00, on-call 24 hrs for a week once every 8 weeks or so.