Arnaldo Tema

Leading the engineering department at Cozero, a carbon accounting and decarbonization SaaS platform. Driving platform stability and technical strategy to support Series B readiness.

• Designing and executing product and engineering strategy for FY2026, aligning technical investments with business goals and Series B milestones
• Audited 4,000+ historical issues to build a data-driven roadmap for platform reliability and customer trust
• Restructured engineering into stability and delivery teams with clear ownership, accelerating output while improving resilience
• Driving core product reliability from ~95% to 99.5%, ensuring emissions calculations customers and auditors can trust
• Cutting critical issue detection time from hours to minutes through proactive monitoring

Led 3 teams (Analytics, Billing, AI) with 20+ engineers, untangling scalability and tech debt. Re-shaped the org to handle bigger clients while staying nimble for SMBs.

• Designed Cloudtalk's Quality Assurance framework, including test coverage, performance testing, and defect management, reducing support-driven defect load by more than 50%
• Established engineering metrics culture tracking DORA metrics, cutting cycle time from 7 days to ~2.5 days
• Introduced an Engineering Review Board with the Product team for our planning cycles, to introduce predictability, improve prioritization, and enforce data-driven decision-making across initiatives.
• Led the revamp of our Analytics system into a 50% performance improvement by defining contracts, rewriting critical MongoDB queries and indexes, and adopting a new sharding strategy
• Led incident response during critical carrier outage, implementing circuit breakers that prevented cascading failures
• The aforementioned revamp reduced infrastructure spend by more than $100K annually
• Launched AI call analytics feature processing 1M+ monthly calls, becoming #2 upsell revenue driver within 5 months
• Shipped real-time sentiment analysis engine with <200ms latency for enterprise sales coaching and conversation insights
• Rebuilt the billing engine from a legacy PHP monolith into a testable, dry-run-enabled TypeScript service powering all subscription flows.

Built the Lisbon team from scratch as we moved from mid-market to enterprise HRIS. Built paved roads so teams could ship fast without losing quality, staying hands-on with architecture and created software for ~150 engineers to adopt.

• Established and led Lattice's Engineering Platform Hub in Lisbon. Built the pilot team, influenced cross-org architecture, and improved platform adoption across 150 engineers.
• Built developer platform and internal tooling that cut new service setup time from multiple days to 40 minutes
• Implemented SOC 2 Type II compliance across platform infrastructure, unblocking more than $2M in enterprise deals previously stalled
• Directed the migration of Lattice's ecosystem to NestJS, creating standards, documentation, and tooling for more than 100 libraries and services.
• Reduced production incidents in 3 months by 20 to 30% by driving adoption of org-wide observability tooling, instrumentation, and best practices.
• Shipped GraphQL API gateway replacing fragmented REST endpoints, which 11 product teams adopted within three months
• Established on-call rotation and incident response playbooks, cutting mean time to recovery from hours to minutes
• Standardized project and delivery processes (Jira + planning cadence), improving predictability across engineering and boosting our engineer's devEx CSAT metrics.

Scaled from 8 to 60 engineers. Led onboarding and partner teams building public APIs and clinic integrations across Europe and North America.

• Built the Test Registration Flow with partner white-labeling using React and Node.js, powering over 30% of all COVID tests in London during the pandemic.
• Grew the product and engineering org from 8 → 60+ people. Built multiple high-performing teams, processes, and the foundational engineering culture.
• Built and led 3 high-performance engineering teams, creating delivery processes, engineering culture, and technical standards from scratch.
• Built Partner API from scratch serving more than 100 medical and clinics across Europe and North America
• Reduced partner API integration time from 8 to 1 week through standardized onboarding and comprehensive documentation
• Implemented rate limiting and API versioning strategy supporting backward compatibility while allowing carriers to adopt new features gradually
• Directed product and engineering strategy through periods of churn, maintaining strong morale and clear execution.
• Defined Hurdle's career progression framework and introduced our delivery practices company-wide.

Built core services and analytics for EVRYTHNG’s Product Cloud, powering GS1-based digital identities and millions of daily scans for brands like LVMH and Coca-Cola.

• Led the development of EVRYTHNG's 99.9% available public API (<0.5s response time).
• Reduced our UI response latency by 50% through CDNs and distributed caching with Redis and optimizing our pub/sub architecture
• Created Terraform modules for all our AWS services, reducing deployment time from hours to minutes
• Partnered with our DevOps Director to introduce blue/green and canary deployment strategies for all our services, reducing downtime and increasing deployment speed
• Built real-time and experimentation analytics (8M+ events/day via Kafka/Kinesis/MongoDB Streams) powering self-serve customer/CS dashboards and 10x faster A/B iteration.
• Designed the company-wide Roles and Permissions system for multiple user tiers (facory users and managers, brand managers, point-in-scan users, end-users, etc)

Joined Sewport as CTO and Lead Developer for a small team of 10.

• Defined and executed the company's technical vision while serving as Lead Developer and Head of Product/Engineering for a 10-person team.
• Migrated a legacy PHP monolith into 10+ scalable Node.js microservices.
• Built engineering practices, agile processes, career frameworks, and product delivery pipelines from scratch.

Built websites and Android apps for national and international clients, handling development, budgets, and client communication. Then joined Die Mobiliar, Switzerland's oldest private insurer, to modernize policy systems and build web services on top of legacy code.

• Was one of the core developers of Portugal's biggest news apps 'Jornal de Negócios' and 'Correio da Manhã'. Used by millions every day.
• Developed internal tools and services for Die Mobiliar - the 2nd biggest insurance company in Switzerland at the time - leading a team of 13 engineers, data scientists and actuaries.
• Mentored 2 junior engineers on API design patterns and best practices for working with legacy systems