Mar 2025 – Sep 2025 · 6 mos · Jaipur, Rajasthan, India · Remote

• This was my second term at Dgraph Labs (Hypermode now). I joined a small team with a goal to stabilizing the database again. I fixed many bugs, re-evaluated some of the earlier changes that had gone into the core engine. Additionally, I enabled support for long desired Unique Constraint in the database. I created dgraphtest package to simplify writing integration tests as well as enable writing chaos tests. All my open source changes are available here https://github.com/dgraph-io/dgraph/commits?author=mangalaman93
• I led the work on building Dgraph k8s operator where we worked on automating most operations work in order to manage the Dgraph instances running in Hypermode cloud.
• I explored and setup monitoring and logging infrastructure using Honeycomb and Axiom for Hypermode Cloud. This has helped us gain deep visibility into the system's behavior in production. I helped design the system for issuing and verifying API Keys and ensured that we follow the security best practices.
• For the v25 release of Dgraph, I worked on a broader effort to rethink the product experience from the ground up. I planned for a new and simpler Dgraph — re-evaluated each existing feature, identified inconsistencies, and proposed changes that make the product easier to understand and adopt. The focus was on removing unnecessary complexity, making defaults more intuitive, and streamlining the user experience. I ensured all changes are backward compatible so that existing users can upgrade smoothly without breaking anything. The API and query language have also been simplified to better align with what users expect from a modern graph database. This release is a big step toward making Dgraph more approachable and practical for everyday use.

Nov 2022 – Feb 2025 · 2 yrs 3 mos · Jaipur, Rajasthan, India · Remote

Jul 2024 – Aug 2025 · 1 yr 1 mo · Jaipur, Rajasthan, India · Remote

• Raj Vidya Kender is a nonprofit that organises Prem Rawat’s events in India and supports the propagation of his message of peace with the help of volunteers.
• I helped set up the IT team — from hiring full-time engineers to onboarding volunteers with the right skills. I setup the infrastructure on GitHub and DigitalOcean to support development and deployment. I setup best practices such as CI & CD using GitHub actions, K8s for staging and prod deployments using Digital Ocean, backend unit and integration testing in nodejs and Golang as well as frontend testing using jest and Playwright.
• We designed a fully offline entry system from scratch for events, where attendees could check in using either a QR Code or an RFID card issued via the website. This ensured smooth entry even in remote areas with poor or no internet connectivity.
• To improve the overall health of the website's codebase, I created a plan to add tests, clean up legacy code, fix long-standing bugs, and introduce new features. We simplified the payment experience and reduced the number of options catering to our users, setup whatsapp integration using Aisensy to reach out to more users — all in collaboration with the rest of the team.

Sep 2020 – Nov 2022 · 2 yrs 2 mos · Bengaluru, Karnataka, India

• At Arista Networks, I have been managing the Zero Touch Provisioning (ZTP) package. ZTP is one of the components of Cloudvision Portal (CVP) which provides a solution to automate networking operations and monitor networks for enterprises and universities. ZTP allows onboarding devices quickly and smoothly on to CVP without requiring any manual intervention.
• ZTP has two components, one is on the device/router side in C/C++ and the CVP side component written in Java/Go. I have fixed various ZTP bugs that have been there since its inception both in the product as well as tests (ctest, unit/integration test). I have also led work for adding various new features such as adding support for certificates without SAN IP, adding support for hardware authentication using TPM 2.0 devices, adding support for web proxy in ZTP.
• Recently, Arista has begun its cloud offering of Cloudvision Portal, CVP as a Service (CVaaS). For ZTP, in the context of CVaaS, the goal has been to provide a smooth and secure onboarding experience while making sure that right device shows up for the right tenant. This required adding support for device embedded token for initial authentication, making hardware authentication using TPM work in cloud context, setting up a pipeline from sales database for mapping device to right tenant, talking to redirector for finding the right cluster for a tenant, enabling onboarding using a USB or a custom bootstrap script.
• I have also been a crucial part of implementing the Ownership Voucher Grpc Service for Secure ZTP (RFC 8572). Ownership Vouchers allow device onboarding even in less secure context by setting up a root of trust using the vendor issued vouchers. This required coordination among various teams, designing the APIs for grpc service, figuring out authentication and authorization for users, finalizing APIs for getting the voucher signed securely using Arista's root of trust as well as getting the service deployed into dev and production with SRE team.

May 2020 – Apr 2021 · 11 mos · Bengaluru, Karnataka, India

• At Doubtnut, I helped the data engineering team setup one of their first data pipelines using Spark and Cassandra (ScyllaDB). I optimized various steps in the pipeline including join with the data in Cassandra by manually querying the data using one query at a time from multiple executors in parallel. I also worked with the Redshift team to optimize queries by correctly choosing sort and distribution key. I setup lambda functions that can transform raw gzipped data into parquet so that queries from Athena are cost effective. I created dashboards using bigquery to provide insights into errors occurred in our Android application using Firebase Crashlytics.
• I also worked on optimizing queries on Aurora and reducing its cost. Using the performance insights, we were able to conclude that the queries are relatively slow on Aurora due to slow disk. I setup an HA cluster of mysql secondary (read-only) on EC2 that could replicate data from Aurora Writer and provide almost 4 times better performance. Aurora Writer provided reliability and availability of the data whereas the secondary cluster provided better performance for analytics and long running queries using local NVMe disks.

Apr 2020 – Feb 2023 · 2 yrs 10 mos · Jaipur, Rajasthan, India · Remote

• Supporting the team with Golang development. I helped the team explore universal authentication for TimelessToday app and website using Ory Kratos & Ory Oathkeeper. Additionally, we decided to migrate the payment gateway for Indian consumers from PayTM and ccAvenue to Razorpay. I helped understand the team the pros and cons for migration and showed a path for integrating the app and the website with Razorpay payment gateway.

Mar 2020 – Apr 2020 · 1 mo

• My focus at Dgraph was to improve the performance, fix bugs and add new features to the database. I added the feature for Upsert and Multiple Mutation in the query language by modifying the compiler and execution engine. I improved the performance of indexing multi folds and reduced the memory usage by using disk for temporary data. I also laid down initial work [1] to show that the Go ecosystem needed a high performance cache and existing caches are not enough which eventually led to Ristretto [2].
• I also enabled Dgraph to compute indexes in the background while still maintaining strong consistency guarantees. This allowed Dgraph to perform mutations and queries even while indexing is going on. I was able to logically prove that all the index changes will be correctly computed for mutations applied before or after indexing command was issued. All my contributions to Dgraph can be found here [3]
• Apart from that, I was the founding engineer of the team in Bangalore and helped grow the team from myself to 16 people when I left. I also ended up adding couple of articles to the pool of excellent blogs that Dgraph has [4].
• [1] https://dgraph.io/blog/post/caching-in-go/
• [2] https://github.com/dgraph-io/ristretto/
• [3] https://github.com/dgraph-io/dgraph/commits?author=mangalaman93
• [4] https://dgraph.io/blog

Feb 2019 – Feb 2020 · 1 yr

May 2018 – Jan 2019 · 8 mos

• My focus at Zeotap was on building, scaling, optimizing and stabilizing various data pipelines and systems. Zeotap deals with billions of records everyday and requires processing terabytes of data fast and efficiently. I built various components of our data pipelines using Spark and Oozie while ensuring consistency of data even when jobs fail. We optimized one of the layers in our data pipeline and reduced its run time from 4 hours to only 20 minutes by correctly identifying the bottleneck. I also worked on setting up and optimizing Redshift, to enable creating segments and run adhoc analysis queries efficiently. I migrated one of our data stores as well as all the data pipelines around it, from Aurora to Aerospike improving performance from 10,000 QPS to more than 300,000 QPS.
• Apart from this, I have spent my time on building and implementing algorithms for attributing revenue back to our data partners. I was able to optimize the algorithm so that it could finish within desired SLA. I also built a system that can estimate size of adhoc segments on billions of records with sub-second latency. This required building a customized in-memory database specifically designed to run queries that can handle flat as well as nested data. The system was implemented using Go for achieving efficiency while ensuing high uptime using fail fast and supervisor tree ideas from Erlang programming language.
• I also helped in building a collaborative culture in our Data Engineering team. I started peer code review process on GitHub to improve the code quality and increase collaboration within the team. To improve communication across teams, I stressed upon the idea of internal tech-talks. I wrote the first engineering blog post at Zeotap to increase exposure outside Zeotap and encouraged everyone in the team to write so that we can better realize and communicate our ideas.

Mar 2018 – May 2018 · 2 mos

• As part of a 3 day company wide hackathon, we (a team of 4 engineers) replaced an external service (Spotinst) used to scale AWS Elastic Map Reduce (EMR) clusters with spot nodes by a custom built service saving more than $50K/year. We utilized insights such as container pending, memory allocated, container running from the yarn cluster scheduler in order to provide shorter job completion times (by faster scale up), better visibility and proactive alerts.
• Zscaler scales up an EMR cluster when jobs are queued on yarn scheduler using spot nodes. It chooses a set of nodes by maximizing a cost function (a non linear LP) that combines node availability, node interruption probability and cost of running the cluster. Once jobs are complete, it will remove the nodes to ensure that the cluster doesn't run idle. If, for some reason, zscaler is not able to add nodes to the cluster, it will notify the cluster admin for a manual intervention.

Apr 2017 – Apr 2018 · 1 yr

Nov 2016 – Jan 2017 · 2 mos · Mumbai Area, India

• Scale the existing Spark cluster to thousands of nodes while adding features such as efficient job scheduling, quick setup for development and production environment, self healing, seamless upgrades.

Jun 2016 – Sep 2016 · 3 mos · Mountain View, California

• Added support for external storage in Zerostack as well as helped in designing architecture to add support for linux containers on top of Zerostack

Jun 2015 – Aug 2015 · 2 mos · Murray Hill, NJ

• Developed an infrastructure to monitor Linux containers using collectd, influxdb and grafana. Also, compared various packing algorithms (server consolidation algorithms) using Discrete Event Time Simulation (DETS) to closely pack containers on a cluster of physical servers.

Aug 2014 – Dec 2015 · 1 yr 4 mos · Atlanta

Mar 2014 – Dec 2014 · 9 mos · Chandigarh, Chandigarh, India

• Designing an Inexpensive, yet high quality, peer to peer wireless technology solution using Interplanetary File System (ipfs)

Jun 2013 – Dec 2013 · 6 mos · Mumbai Metropolitan Region

• Developed an Erlang Package Manager (epax)

May 2013 – Jun 2013 · 1 mo · Greater Chennai Area

• Built a dashboard to visualize performance and status of production cluster using Geckoboard and Ruby

Dec 2012 – Dec 2013 · 1 yr · Mumbai Metropolitan Region

• Developed a back-end application for intelligent agent selection for IVR applications

Dec 2011 – Dec 2011 · 0 mo · Mumbai Metropolitan Region

• Prepared questions for Ikenscientifica, the international science competition for kids.