Senior Backend Engineer, Sessions & Workflows

MaC VC; San Francisco (CA); On-site; USD 140,000 - 230,000; Full time

Job summary

MaC VC is building serverless systems to orchestrate annotation sessions, matching tasks to annotators, managing work queues, and ensuring quality at scale across a global workforce.

You will own the real-time workflow engine that powers production labeling, with responsibilities spanning session orchestration, performance monitoring, and cross-border collaboration with teams in San Francisco and Nairobi.

Qualifications

• 4+ years building production backend systems.
• Strong TypeScript and Node.js experience.
• Experience with serverless architectures (Lambda, SQS, Step Functions).
• Knowledge of PostgreSQL, Redis, and distributed systems patterns.
• Experience with real-time systems or workflow orchestration.

Responsibilities

• Design and build serverless functions (AWS Lambda, Step Functions) for session orchestration.
• Optimize task matching algorithms that assign work based on skill, quality, and availability.
• Build real-time monitoring dashboards for annotation throughput and quality metrics.
• Implement workflow automation for multi-stage QC review pipelines.
• Scale the sessions system to handle 10x growth in concurrent annotators.
• Collaborate with operations teams in SF and Nairobi to optimize workforce utilization.

Skills

Backend development

TypeScript

Node.js

Serverless architectures

Real-time systems

Tools

AWS Lambda

AWS SQS

AWS Step Functions

PostgreSQL

Redis

Job description

Build the serverless systems that orchestrate Avala's annotation sessions — matching tasks to annotators, managing work queues, and ensuring quality at scale across our global workforce of 15,000+ domain experts. You'll own the real-time workflow engine that powers production labeling.

What You'll Do:

• Design and build serverless functions (AWS Lambda, Step Functions) for session orchestration
• Optimize task matching algorithms that assign work based on skill, quality, and availability
• Build real-time monitoring dashboards for annotation throughput and quality metrics
• Implement workflow automation for multi-stage QC review pipelines
• Scale the sessions system to handle 10x growth in concurrent annotators
• Collaborate with operations teams in SF and Nairobi to optimize workforce utilization

Requirements:

• 4+ years building production backend systems
• Strong TypeScript and Node.js experience
• Experience with serverless architectures (Lambda, SQS, Step Functions)
• Knowledge of PostgreSQL, Redis, and distributed systems patterns
• Experience with real-time systems or workflow orchestration

Nice to Have:

• Experience with workforce management or marketplace platforms
• Familiarity with annotation or data labeling systems
• Experience optimizing for latency-sensitive, high-throughput workloads