Andrés Ruiz Justo

As a Senior Software Engineer with extensive experience across fintech, SaaS, and telecommunications, I thrive on building scalable, resilient systems that solve real-world problems. My career has taken me from Mexico to Singapore, where I’ve led impactful projects at companies like Wise, abillion, and Circles.Life.

At Wise, I spearheaded large-scale data migrations-filtering 660 million transactions and backfilling 57 million records in under a week without service interruption. I pioneered QR payment solutions, including launching Swiss QR (cutting customer contacts by 50% and boosting transactions by 25%) and PIX, now Brazil’s most popular QR payment method. I also led the expansion of Wise’s card product into Indonesia, enabling INR payments and driving £1M in monthly organic transactions.

Previously, I drove the development of abillion’s Business Dashboard, empowering brands with actionable insights, and led backend and database refactoring to ensure scalability. At Circles.Life, I helped launch telecom solutions in Taiwan and Australia, contributing to the company’s rapid regional growth. Earlier in my career, I dramatically improved code reliability at Guds SAPI de CV, raising coverage from 0% to 90%.

My technical strengths include Java, TypeScript/JavaScript, Spring, SQL/NoSQL databases, Redis, and distributed systems (Kafka, gRPC). I’m passionate about software design, architecture, and leading high-performing teams. I communicate fluently in English and Spanish, with working proficiency in French and Galician, and basic Korean.

I’m always eager to tackle complex challenges, collaborate across cultures, and explore new technologies that drive business impact.