Simon Willison’s Weblog

Where is Twitter’s office in London?

Just off Great Portland Street.

How do I quit the startup I founded without causing too much fallout?

Have you discussed your situation with your investors? They are likely to strongly prefer you taking a larger salary than stepping down or taking on consulting work.

How is a dictionary (key value) related to a hash?

The following terms describe essentially the same data structure across a number of different languages:

• A Perl hash
• A Ruby hash
• A Python dictionary
• A Java Map (an interface used by HashMap and others)
• A Lua table
• A JavaScript object (if you ignore object prototypes)

What are good ways to rewrite a social network and still keep old users?

Don’t rewrite. If you’re going for a major overhaul, do it in as many small steps as possible. Massive rewrites are a great way to completely kill all forward motion on your product.

Professional Networking: How can I find on the internet an expert in a given field?

We launched a speaker directory for Lanyrd recently that might help here—it lists the most prolific speakers for thousands of topics, based on our dataset gathered across many conferences around the world.

How do you recruit programmers without risk of them leaving and jacking your idea, especially without initial funding?

You could ask them to sign a non-compete (which I believe are non enforceable in some jurisdictions, including California) but you might find this deters some skilled programmers.

Is there a way for a user of a site (no database) to add their own notes to a webpage, so when they return (regardless of the device), their notes are shown?

There have been plenty of attempts at building web annotation systems like this in the past—I actually built one for my final year university project a decade ago—but they all suffer from the same problem: web pages change, and once they have changed the annotations may no longer be attached to the right place in the document.

Why is postgresql popular with django?

Partly because the first applications developed on Django (before it was even called Django) used PostgreSQL, so it’s had great PostgreSQL support baked in from the start.

Are there any websites, forums, or blogposts that discuss startups’ technology stacks or IT infrastructure?

The website www.highscalability.com has a good collection of articles on this topic (case studies about specific startup’s technology stacks) stretching back several years.

What are some of the best programming/technical questions on scalability?

“How would you architect Twitter?”

How can you run image processing in cloud code (Parse) ? If parse is not the best

There are dozens of web-based image resizing APIs that could help with this. Check out http://www.imgix.com/ for example.

Should I store markdown instead of HTML into database fields?

You should store the exact format that was entered by the user.

What is the best way to choose between two equally feasible start-up ideas?

Which one is most likely to still be exciting to you in five years time?

What are some resources to read when designing a new client-server application layer protocol?

I suggest avoiding designing a custom protocol and using Protocol Buffers, Apache Thrift or Cap’n Proto instead.

Which tools top technology companies use to create complex web pages e.g Amazon Home Page, Facebook etc? Do they create it manually or use some tool like Dreamweaver ?

The code (HTML/CSS/JavaScript) will be written by hand, usually by a large team of people who have evolved it over several years. They’ll be working with some kind of server-side technology as well, usually involving a templating language.

Should a beginner to web development start out with Node.Js?

Maybe. One of the things I like about Node.js is that the raw abstraction it provides over HTTP is much closer to how the actual protocol works than the abstractions provided many of the more widely used frameworks such as PHP, Django or Rails. That might actually make it an effective learning tool—I’d be interested in hearing from some web developers who learnt Node.js as their first server-side technology.

How should two equal startup founder formalize a cliff?

A company is a legal entity. The person who leaves the company is the person who resigns from that legal entity.

Great Britain: As a Briton, do you feel any pride for being so?

The only two things that make me feel patriotic are the 2012 Olympics opening ceremony and the Great British Bake Off.

Getting the most out of technical conference as a services provider?

Leaving flyers out if you are not a sponsor will annoy both the event organiser and the other sponsors, and may give a bad impression to other attendees as well.

Does Paul Graham steal business models from teams not accepted into Y Combinator and feed them to accepted teams as pivot ideas?

No. If he did, word would quickly get around and strong teams would stop applying to YC.

I would like to attend a Big Data conference but I am short of funds. Is there any big data conference that helps students attend those conference through scholarship?

The traditional route for students who can’t afford to attend a conference is for them to volunteer. Contact event organisers of Big Data conferences that look relevant and ask if they are looking for volunteers.

What are key considerations when building behind the firewall web apps?

CSRF and XSS are still important: don’t leave any security vulnerabilities which might allow an evil website out on the internet to run JavaScript that steals data from your behind-the-firewall web application.

How can I sell an idea to investors?

At minimum: build a prototype. If you really want then to take seriously, launch a first version and demonstrate traction.

How do I become a global nomad as a software engineer?

Go freelance, start working on projects and build up a reputation as an excellent engineer who gets high quality work done on time. Build up a large roster of satisfied clients who wish to work with you in the future, and know how to successfully work with you via email and video conferencing. Now pack your laptop and head off around the world.

Event Planning: What can I do to protect myself from a keynote speaker not showing up?

My hunch is that if a keynote speaker doesn’t show up it won’t be for financial reasons—and they wouldn’t expect their fee to be paid. Much more likely it would be a family emergency or unexpected travel problem.

How come Quora hasn’t contributed any significant open source tools?

Releasing open source software is a lot of work. You need to extract it from your own proprietary systems, clean it up, document it, release it and them deal with support queries, incoming bug fixes, suggestions and feature requests.

What are some techniques, workflows, thought-processes etc. you would do as an experienced web-developer (front-end/back-end) that a new web developer might benefit from?

Learn the Chrome Developer Tools inside out, and live in them—especially the interactive JavaScript console, which can be a huge boon to your productivity.

What are some good open source projects that VMware is directly part of?

To my knowledge they fund almost all of the development work on RabbitMQ, Redis and the Spring Java framework.

What can startups do on big data day one?

Log everything, and then forget about it. That way you’ll have data you can analyse later on, but aside from setting up logging and log storage you won’t waste any time messing around with Big Data when you haven’t yet found product-market fit.

Event Planning: What are some useful books and resources on professional events and conference planning?

http://www.quirksmode.org/coh/ is fantastic. It focuses on running small tech conferences, but there’s plenty of advice in there that applies to all sizes of event.