John Bennedict Lorenzo, Developer in Berlin, Germany
John is available for hire
Hire John

John Bennedict Lorenzo

Verified Expert  in Engineering

Bio

JB is currently the CTO at an HR tech startup. He has developed iOS and Android apps, focusing on design and usability while maintaining a low bug rate. JB has managed technical teams for more than a decade and is skilled in hiring, evaluating, mentoring, and coaching technical people.

Portfolio

Papayo
Technical Hiring, CTO, Fractional CTO, Google AI Platform, Gemini API...
OLX
Swift, Kotlin, TypeScript, Amazon Web Services (AWS), Spring Boot, Android, iOS...
Seeds, Inc. (via Toptal)
Extensions, Swift, Mobile Development, Mobile App Development...

Experience

  • Objective-C - 12 years
  • iOS - 12 years
  • Android - 11 years
  • Swift - 6 years
  • Java - 4 years
  • Facebook SDK - 4 years
  • Google AI Platform - 2 years
  • Parse - 1 year

Availability

Part-time

Preferred Environment

Flutter, Amazon Web Services (AWS), Team Leadership, CTO, Google Cloud Platform (GCP), TypeScript, Android, iOS, PostgreSQL, Python

The most amazing...

...software I've built was for a client that uses beacons and a CMS to send alerts to users based on their indoor location.

Work Experience

CTO

2024 - PRESENT
Papayo
  • Implemented a sub-second semantic search on 14 million rows of profile data.
  • Hired a team of seven engineers to build the product from the ground up.
  • Launched the pilot to around 10 customers to get feedback before the market launch.
  • Implemented AI agents to perform search, scoring, and outreach.
Technologies: Technical Hiring, CTO, Fractional CTO, Google AI Platform, Gemini API, Back-end Development, Large Language Models (LLMs), Artificial Intelligence (AI), Web Development, API Integration, Natural Language Processing (NLP), AWS Certified Solution Architect, Python, OpenAI API, APIs, Node.js, React, App Design, Technical Leadership, Database Architecture, Agile Software Development, CI/CD Pipelines, Data Structures, Databases, SQL, Software Architecture, JavaScript, Tailwind CSS, Content Management Systems (CMS), Back-end, AWS Lambda, Amazon DynamoDB, Serverless, DevOps, CSS, HTML, Prompt Engineering, Amazon RDS, Amazon S3 (AWS S3), Amazon Simple Queue Service (SQS), OpenAI, Mobile Apps, Data Engineering, Data Pipelines, Agentic AI, ChatGPT, Front-end

Engineering Manager

2017 - 2024
OLX
  • Managed a team of up to 12 cross-functional developers, including back-end, front-end, and mobile engineers.
  • Served as a mobile hiring sponsor for all three CUs across Europe, establishing hiring practices and standards that improved interviewer NPS from 50% to around 70% in six months.
  • Increased delivery adoption in Poland from 48% to 66% and in Romania from 8% to 17%. Launched the most number of experiments among teams in one quarter.
  • Led the development of a multi-tracker SDK for iOS and Android, orchestrating AppsFlyer, Adjust, Mixpanel, Hydra (internal tracking solution), and more.
  • Led the development of a rich push notification SDK for iOS and Android, rendering push notifications with images and templated content via an internal push CRM.
Technologies: Swift, Kotlin, TypeScript, Amazon Web Services (AWS), Spring Boot, Android, iOS, Data Management, A/B Testing, Technical Hiring, Performance Management, Technical Project Management, CTO, JavaScript, Full-stack, User Interface (UI), Architecture, PHP, Redis, Back-end Development, Artificial Intelligence (AI), Web Development, API Integration, AWS Certified Solution Architect, Python, Podfile, Dependency Management, MacOS, Objective-C, APIs, React, Mobile, Dart, Apps, Technical Leadership, Database Architecture, Agile Software Development, CI/CD Pipelines, Data Structures, Databases, SQL, Software Architecture, Flutter, Firebase, Content Management Systems (CMS), Back-end, AWS Lambda, Amazon DynamoDB, Serverless, DevOps, HTML, Prompt Engineering, Amazon RDS, Amazon S3 (AWS S3), Amazon Simple Queue Service (SQS), OpenAI, Mobile Apps, Data Engineering, Data Pipelines, ChatGPT, Large Language Models (LLMs), Front-end

iOS Developer

2016 - 2016
Seeds, Inc. (via Toptal)
  • Developed a keyboard extension using Swift.
Technologies: Extensions, Swift, Mobile Development, Mobile App Development, User Interface (UI), Architecture, API Integration, Podfile, Dependency Management, APIs, Mobile, Apps, Agile Software Development, Mobile Apps, Front-end

iOS Engineer

2015 - 2016
Fankave (via Toptal)
  • Co-developed a Swift application.
Technologies: Swift, Mobile Development, Mobile App Development, Social Media Apps, User Interface (UI), Architecture, Startups, API Integration, Podfile, Dependency Management, Objective-C, APIs, Mobile, Apps, Agile Software Development, Mobile Apps, Front-end

Lead Software Engineer

2011 - 2015
Stratpoint Technologies
  • Created iOS and Android apps for a major coupon service in Singapore.
  • Created sports/media apps for a software development partner. They follow the design guidelines very well, resulting in unique user experiences for each.
  • Led a team that ported a credit card sharing app to Android for parents to their kids via an accredited service.
  • Integrated apps to a client's solution framework that enabled indoor location services and dynamic pages.
Technologies: Android, iOS, Mobile Development, Mobile App Development, Application Security, Security, User Interface (UI), Architecture, Video Streaming, Back-end Development, API Integration, Python, Podfile, Dependency Management, Objective-C, APIs, Node.js, Mobile, App Design, Apps, Technical Leadership, Database Architecture, Agile Software Development, CI/CD Pipelines, Data Structures, Databases, SQL, MySQL, Software Architecture, Firebase, JavaScript, Back-end, AWS Lambda, Amazon DynamoDB, Serverless, CSS, HTML, Mobile Apps, Front-end

Experience

NFL '12

Lead iOS developer for NFL '12, NFL '12 International. Co-developer for NFL Mobile (Canada). Integrated the previous iPhone and iPad apps into a universal app. Integrated the second screen experience called TNF Xtra and AFL Xtra from Visiware. Transitioned development script to allow generating enterprise builds that can be installed alongside the debug and production builds. Implemented the pre-season, regular season, and Superbowl season changes for the app.

NFL '13

I was the lead iOS developer for NFL '13, NFL '13 International, and NFL Mobile (Canada). I implemented the draft season and pre-season releases for the app and worked with other software engineers to complete releases on schedule, e.g., during the draft season.

Oink

Credit card sharing application for parents and kids. Developed the app directly from designs, as pixel-perfect as possible, using APIs provided by the client. Worked with a team to perform QA, design decisions, and tech decisions.

Dart Apprentice

https://www.kodeco.com/books/dart-apprentice-beyond-the-basics/v1.0/chapters/iv-about-the-team
Dart Apprentice is aimed at anyone interested in learning this new and modern programming language. If you're a beginner and want to start programming, this is a great place to start. If you're an experienced programmer interested in learning Dart, you'll find all the concepts you need to know here. In either case, following along with this book, you'll be comfortable writing your own Dart programs in less time than you think.

Ritual Mobile

http://ritual.work
Ritual transforms team-based problem-solving through workflows and AI.

We help teams overcome problem-solving challenges as they progress from initial ideas to achieving impact.

This means simple and powerful ways to accomplish upstream work: define problems, gather input, and develop answers. Doing these things well unlocks everything that follows: recommendations, alignment, and decisions.

Kodeco

https://www.kodeco.com/u/bennegeek
Since 2019, I've been writing multiple tutorials and books on Android and Flutter. My latest contribution is as the final pass editor of a learning module on Kotlin classes. The Dart Apprentice book is followed by two other editions.

Education

2014 - 2017

Master's Degree in Computer Science

University of the Philippines Diliman - Diliman, Quezon City, Philippines

2007 - 2011

Bachelor's Degree in Computer Engineering

University of the Philippines Diliman - Diliman, Quezon City, Philippines

Skills

Libraries/APIs

OpenAI API, Node.js, Facebook SDK, React

Tools

Google AI Platform, Amazon Simple Queue Service (SQS), ChatGPT, Android Studio, Xcode

Languages

Objective-C, Swift, Dart, TypeScript, JavaScript, PHP, Python, SQL, Java, CSS, HTML, Kotlin

Frameworks

Flutter, Tailwind CSS, Spring Boot

Paradigms

Mobile Development, Agile Software Development, DevOps

Platforms

Android, iOS, Amazon Web Services (AWS), Mobile, AWS Lambda, Firebase, MacOS, Parse, Arduino, Google Cloud Platform (GCP)

Storage

Redis, Amazon DynamoDB, Amazon S3 (AWS S3), Data Pipelines, Database Architecture, Databases, MySQL, PostgreSQL

Other

Team Leadership, Mobile App Development, Social Media Apps, User Interface (UI), Architecture, Cross-platform App Development, Fractional CTO, Gemini API, Back-end Development, Large Language Models (LLMs), Artificial Intelligence (AI), API Integration, AWS Certified Solution Architect, Podfile, Dependency Management, APIs, Apps, Technical Leadership, CI/CD Pipelines, Data Structures, Software Architecture, Back-end, Serverless, Prompt Engineering, Amazon RDS, OpenAI, Mobile Apps, Data Engineering, Agentic AI, Front-end, CTO, Full-stack, Video Streaming, Startups, Web Development, Audio, App Design, Content Management Systems (CMS), Extensions, Data Management, A/B Testing, Technical Hiring, Performance Management, Technical Project Management, Application Security, Security, Technical Writing, Documentation, Natural Language Processing (NLP)

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring