Senior Backend Developer (PHP)

About Massive Bio
Every cancer patient deserves access to treatment options. Massive Bio is an AI-powered precision medicine platform transforming how cancer patients discover and access clinical trials by eliminating the barriers of geography, financial constraints, and information asymmetry that have historically limited enrollment.

Founded in 2015 and headquartered in US, Massive Bio is scaling its impact globally by powering operations across multiple countries and bringing innovative cancer treatment options to a rapidly growing and diverse population of patients. Through our proprietary AI platform, we connect individuals to clinical trials worldwide and partner with leading pharmaceutical companies, contract research organizations (CROs), and healthcare systems to accelerate drug development and expand equitable access to cutting-edge therapies.

We're recognized as a leader in health-tech innovation. Massive Bio was featured as #4 in Fast Company's Startup 100 list for Turkey and has raised $24M total funding from impact-driven investors including Revo Capital, the International Finance Corporation, and Cavendish Impact Foundation, validating both our business model and our mission-driven approach.

Role Summary
As Senior Backend Developer (PHP), you will be a key member of our Software Development team, responsible for the implementation and maintenance of scalable web applications and services. You will develop high-performance, reliable, and maintainable code with a strong customer focus, collaborating closely with peers across product, back-end, business intelligence, and quality assurance.

What You’ll Do

• Develop and support software including applications, database integrations, interfaces, and new functionality enhancements

• Write high-performance, reliable, and maintainable code

• Build software with a strong customer focus and collaborate closely with cross-functional peers (product, back-end, business intelligence, quality assurance)

• Contribute to implementation and maintenance of scalable web applications and services

• Work within Agile development processes and tools to deliver improvements and enhancements efficiently

Who You Are

• Minimum 5 years of experience in PHP, Laravel, TypeScript, and MySQL

• Experience with MVC pattern

• Experience with RESTful web APIs and JavaScript, jQuery, and AJAX technologies

• Experience with CSS and HTML

• Experience with ORMs

• Knowledge of Design Patterns, Data Structures, and SOLID Principles

• Experience working with PhpUnit

• Knowledge of Microservices architecture

• Experience with Jira, Agile development processes, Git, and continuous integration

• Bachelor’s degree required (engineering preferred) or a related field

• Proven results influencing stakeholders and driving improvements

• Ability to translate complex problems and ideas into easily understood descriptions

• Ability to work independently; self-starter with a can-do attitude; able to multitask and prioritize

• Experience in healthcare technology is a plus

• Good verbal and written communication skills in English